SWAMI PARMANAND COLLEGE OF ENGINEERING & TECHNOLOGY

SIX MONTHS INDUSTRIAL TRAINING REPORT

ON

NETWORKING (MCSE & CCNA)AT

JETKINGSEC 34 , CHANDIGARH

SUBMITTED AS A PART OF COURSE CURRICULUM

BACHELOR OF TECHNOLOGY

IN

ELECTRONICS & COMMUNICATION ENGINEERING

Under the Guidance of

Mr. Baljit singhMr. Inder Gulati

Submitted To: Submitted By: Er. Harpreet Kaur (HOD) Saroj Dogra (697041917)

DEPARTMENT OF ELECTRONICS &COMMUNICATION ENGINEERING

SWAMI PAMANAND COLLEGE OF ENGINEERING & TECHNOLOGY, DERA BASSI, MOHALI

ACKNOWLEDGEMENT

I feel deeply indedted to Mr. Baljit Singh, Microsoft trainer who delivered valuable

lesson on MCSE, his indepth knowledge about the subject helped me understand the

subject in better way. His method of teaching the minute details helped me a lot to

acquire the insight into the subject.

I am also grateful to Mr. Inder Gulati, CCNA trainer for giving best knowledge about

CCNA.the way he instilled knowledge of the subject was undoubtly praise worthy and

valuable.

I am also thankful to Jetking institution as a whole that is doing yeoman’s service by

teaching the learner avreast with the computer , networking and hardware knowledge that

is the need of the day.

I will be failing in my duty if I do not acknowledge my husband Mr. Nardev Singh Rana

who always stood by my side during my studies. I am indepted to my son’s Anirudh

Rana and Romil Rana who never clamed my time and get bore by my long absence rather

silent.

Last but not the least, I thank all my classmates at Jetking for extending kind

co-operation.

SAROJ DOGRA

List of Figures

Figure No. Name of Figure Page No.

1 Computer network 6

2 Local Area Nework 9

3 LAN Classification 9

4 Campus Area Network 10 5 Metropolitan Area Network 11

6 To find location of a computer using FQDN 24

7 Tree structure 25

8 Structure of domain forest and domain tree 36

9 Multi-Master Mode 37

10 Parent child relationship model 40

11 Direct Sharing Scenario 43

12 ICS scenario 44

13 Scenario of win proxy server 45

14 NAT Server 46

15 VPN server 48 16 LAN routing 52

17 Static routing 53

18 Architecture of router 60

19 Variable Subnet Mask 75 20 Scenario of Telnet 76

21 Scenario of Static Routing 81

22 Routing table 86

23 Routing table of covered networks 86

24 Routing loops 87

25 OSPF Scenario 99

26 VLAN Operation 105

27 VTP Configuration 110

28 VTP Pruning 111

29 IEEE 802.11 Standard 114

List of tables

Table No. Name of table Page No.

1 Difference between Workgroup & Domain 7

2 Comparison between IPv4 and IPv6 12

3 Address Classes 13

4 Category and Speed of UTP cables 17

5 Colour Coding for straight Cable 18

6 Colour Coding for Crossover cable 19

7 Colour Coding for Rollover Cable 20

8 Operating Systems 21

9 Difference between Workgroup and Domain 34

10 Exchange Server with different operating systems 56

11 Router interfaces and connectors 62

12 Router Ports 63

13 Default address mask in binary & dotted decimals 71

14 Decimal and Binary values of subnet mask 72

15 Subnet mask, valid hosts, broadcast address 74

16 Routing table 86

17 Difference between RIPV1 & RIPV2 90

18 Difference between IGRP and RIP 91

CONTENTS

Sr. No. Topic Page No.

1 INTRODUCTION 1 1.1 Company Profile 12 LITERATURE RIEVIEW 53 NETWORKING 6

3.1 Introduction to networking 6

3.1.1 Models of Networking 6

3.1.2 Categories of network 8

3.2 IP ADDRESSES and MAC Addresses 12

3.2.1 IPAddressClasses 12

3.2.2 MAC Addressing 15

3.3 NETWORKING MEDIA 15

3.3.1 Ethernet Cabling 17

3.4 OPERATING SYSTEM 20

3.4.1 Types of Operating Systems 20

3.5 DNS SERVER 22

3.5.1 PARTS OF DNS SYSTEM 23

3.5.2 DNS Zone 26

3.6 DHCP SERVER 28

3.6.1 Working of DHCP Server 29

3.6.2 InstallationStepsofDHCPServer 31

3.7 ACTIVE DIRECTORY 33

3.7.1ActiveDirectoryServices 34

3.7.2 CHILD DOMAIN 40

3.8 INTERNET SHAREING 42

3.8.1 Direct Sharing 42

3.8.2 ICS (Internet Connection Sharing) 43

3.8.3 Win Proxy Server 45

3.8.4 NAT (Network Address Translation) 45

3.9 VIRTUAL PRIVATE NETWORK (VPN) 47

3.9.1 VPN components 48

3.9.2 Types of VPN 49

3.10 ROUTING 51

3.10.1 Types of Routing 51

3.11 EXCHANGE SERVER 56

3.11.1 Elements of Exchange Server 56

3.11.2 Exchange Version 56

3.11.3 Requirements for Exchange Server 57

3.12 Open System Interconnection (OSI) Model 57

3.12.1 Description of Different Layers 58

3.13 ROUTERS 60

3.13.1 Router Architecture and its Key Component 60

3.13.2 Router Interfaces & Ports 62 3.13.3 Modes of Router 63

3.13.4 Configuring Password 65

3.13.5 Managing Configuration 66

3.14 SUBNETTING 70

3.14.1 Advantages of subnetting 70

3.14.2 Types of Subnetting 73

3.15 TELNET 75

3.15.1 To Access the Device Remotely 75

3.15.2 Commands to assign IP addresses to the interfaces 76

3.16 ROUTING 79

3.16.1 TYPES OF ROUTING 79

3.16.2 Routing Protocol Basics 84

3.1.3 R IP (Routing Information Protocol) 88

3.1.4 IGRP ( Interior Gateway Protocol) 91

3.1.5 EIGRP(Enhanced Interior Routing Protocol) 93

3.1.6 OSPF (Open Shortest Path First) 95

3.17 LAN SWITCHING 100

3.17.1 SWITCH 100

3.17.1.1 VLAN (Virtual LAN) 103

3.17.1.2 Vlan Trunking Protocol (VTP) 108

3.18 Wi-Fi (WIRELESS FIDELITY) 113

3.18.1 Wireless LAN 113

3.18.2 Wireless Standards 114

3.18.3 Wireless Security 115

4 CONCLUSION 117

5 REFRENCES 118

1. INTRODUCTION

This project report pertains to six months industrial training that I had underwent

at JETKING, Chandigarh as part of curriculum of degree in Bachelor of technology in

Electronics and Communication engineering as required by Swami Parmanand College of

engineering and technology (affiliated to Punjab Technical University, Jalandhar) .

I learnt a lot from professional managers and skilled engineers. I had a great

learning experience as trainee in this firm. I learnt a lot about how different networks are

controlled in the industry or any department with the help of networking processes, under

MCSE and CCNA.

I have learnt about different type of servers like DHCP Server, DNS Server, NAT

Server. Also I have learnt how to control the LAN and MAN networks under MCSE

(Microsoft Certified System Engineers) and how to control MAN and WAN networks

under CCNA (CISCO Certified System Engineers).

Justification cannot be done to whatever I have learnt in these six months within a

few pages but I have still tried my best to cover as much as possible in this report. In this

report I have tried to sum up the technical knowledge I have gained in my six months of

training.

1.1 Company Profile

Jetking is an organization came into establishment in1947. Jetking is India’s

number one Computer Hardware and Networking Institute.

Birth and Evolution

It took a lot of failure before mankind tasted technological success. Jetking evolved in

tune with the changing face of technology. During 55 years in the field of electronic

technology. Jetking successfully trained thousands of students to overcome failure for

high paying careers.

1947 Birth

1962 Pioneered “Do-It-Yourself Kits” in India

1972 Introduced Asia- 72, Fairchild and Wildcat transistors

1986 Became a Public Limited Company and also introduced

entertainment electronics product-T.V sets, Two-in-ones and

amplifiers.

1990 Launched Jetking School of Electronics Technology

1993 Network of Jetking training centers spread all over India

1994 Opening of Jetking, Chandigarh

1995 Tie-up with Heath kit Educational System (U.S.A.)

1996 Introduced advanced courses on Pentium, Notebooks, Modems,

Email/Internet, LAN 4.X

1997 Novell Education Academic Partner

1998 Representative for International Correspondence School (ICS),

USA in India

1999 Added cyber technology to the curriculum

2003 ISO 9001-2000 company and Authorized Microsoft online testing

centre (VUE) for MS, CISCO, MCSA, MCSE, CCNA, A+ etc.

Mr. Suresh G. Bharwani is the CHAIRMAN and MANAGING Director of

Jetking Infotrain Ltd. India’s leading Computer Hardware and Networking Institute. With

the vision to promote and the conviction to deliver the widespread propagation of comp-

uter hardware and networking education across the nation, Mr. Bharwani was the first to

set up an training institute offering innovative courses in computer hardware in 1990.

Jetking’s core competency lies in providing complete training and developing hardware

engineers and professionals with sound technical knowledge. It focuses on the overall

development of personality of an individual with emphasis on personality development,

presentation and communication skills, leadership skills etc.

Jetking has established more than 125 operational centers and 250 faculties across

the country and has trained over 3,50,000 students who have move onto the crave

success- full career. With its alumni placed in the best of organizations in India and some

abroad,

Jetking,s vocational training and placement promises has helped build the career

prospects of many young boys and girls.

The company has been awarded the ISO 9000:2000 certification in 2003.The

company has been awarded the “ Maharashtra IT Award” for a key role in manpower

activities in year 2006-07,it was felicitated with Franchise Award as Best Franchisor for

the year 2007-08.Also,ranked 4th in the list of 26th hot franchises as per outlook money

magazine.

Mr. Suresh Bharwani was awarded with “Pike’s Peak Award” by the Bob Pike

Group USA for effective implementing smart lab plus for making technical training fun,

faster and easier for non- technical person.

Across all the sectors, industries are upgrading their information technology

system. Industries ranging from plastics, chemicals, textiles and power to the automotive

and telecom sector are now IT savy. Government and public sectors are going hi-tech

with EDI and computer networks. The IT industry, software companies, data centers, IT-

enabled services providers are all equipped with advance IT system and networks. The

increasing number of call centers, BPO’s etc., have given a further boost to the hardware

and networking industry.

The courses in jetking comprises lecture and theory session, with a great focus on

active participation through smart lab plus ,that focuses on audio visual and learning with

hands-on training and equips students with an in depth domain knowledge that is

technical; it also equips students with soft skills ,to face the multi-faceted challenges of

corporate world.

PLACEMENT: Jetking is the first and only institute that promises the 100%

jobs guarantee to its students. The companies that have recruited jetkings students

include:

Samsung, Sun Micro system, IBM, Canon, Siement, reliance, TATA, Compaq HP

invent, IT-T solutions, Videsh Sanchar Nigam Limited, D-Link, Novell, Dell, Wipro, LG,

ICIC Infotech and several other MNCs.

Any student who has qualified his or her HSC/SSC examination is eligible to take

up a course at jetking. The one year program Jetking certified hardware and networking

professionals give 680 hours of in-depth knowledge to a student in Basic electronics and

computer applications. Computer hardware and peripherals, window 2003 administrator

and network administrator (soon it will be replaced with window server 2008).Apart

frame technical knowledge there are personality development sessions which groom the

student’s personality, their ability to perform better.

Jetking, India’s leading hardware and networking training institute has trained

over 3,00,000 students from its 125 centers spread across India. With its alumni placed in

the best of organizations in India and some abroad, Jetking vocational training and

placement promises has helped build the career prospects of many young boys and girls.

Jetking has partnered with some of the worlds most renowed names in networking

to provide you with cutting edge courses and technologies. With academic partnerships

with Microsoft, Comp TIA,LINUX, NOVELL, and person VUE .

Jetking Chandigarh is a division of Hi-Tech point. Hi-Tech point is an ISO 9001-

2000 IT company. It was established in year 1993 and run by a company of IT

professionals. Jetking Chandigarh branch is considered to be the best centre among all

centers. It has bagged number 1 center award consecutively for last 7 years. Here training

on various fields is going on like Basic Electronic, Hardware, Networking, JCHNP

Analog and Digital electronics and Hardware, RHCE, RHCSS, MNA, MCSE (Microsoft

System Engineers), MCITP, MNA, CCNA (CISCO Certified Network Associate),

CCNP(CISCO Certified Network Professional).

Partnership with industry leaders like Microsoft and Red Hat Jetking ensure its

students authentic courseware and technology.

2. LITERATURE RIEVIEW

Computer Networking is a very vast project in the present developing era of electronics

and communication. Now a days, computers are used in a wider range. All the

organizations are using multiple computers within their departments to perform their day

to day work. Computer network allows the user to share data , share folders and files with

other users connected in a network. Computer Networking has bound the world in a very

small area with it wide networking processes like LAN, MAN, WAN.

The courses in jetking comprises lecture and theory session, with a great focus on active

participation through smart lab plus ,that focuses on audio visual and learning with

hands-on training and equips students with an in depth domain knowledge that is

technical; it also equips students with soft skills ,to face the multi-faceted challenges of

corporate world.

3. NETWORKING

3.1 Introduction to networking

Networking is a practice of linking of two or more computing devices such as

PCs, printers, faxes etc., with each other Connection between two devices is through

physical media or logical media to share information, data and resources. Networks are

made with the hardware and software.

Cable/media

Fig 1: computer network

3.1.1 Models of Networking

Model means the connectivity of two computers. We have many types of

networking models.

(i) Client – Server Model

(ii) Peer to Peer Model (Workgroup Model)

(iii) Domain Model

(i) Client –Server Model

In a Client server model we have one server and many clients. A Client can share

the resources of server, but a server cannot share the resources on clients.

On the point of view of administrator it’s very easy to control the network

because we combine with the server also at security point of view. It is very useful

because it uses user level security in which users have to remember only one password to

share the resources.

(ii) Peer to Peer Model (Workgroup Model)

In Peer to Peer networking model all computers are in equal status, that is we

cannot manage centralization, administration secutity. In Peer to Perr networking client

use operating system like Window 98, Window XP, Window 2000, Window Vista.

(iii) Domain Model

It is a mixture of client server and peer-to-peer model. In this clients can share

their resources as peer-to-peer but with the permission of the server as in client server

model therefore it is commonly used model because in this security is more as we can put

restriction on both server and clients.

Difference between Workgroup & Domain

Table 1

Workgroup Domain

1. It is a peer to peer networking model.

2. There is no client and no server. All the

computers are in equal status.

1. It is a server based networking model.

2. There is a centralized dedicated server

computer called domain controller which

3. This model is recommended for small

networks, upto 10 computers.

4. There is no centralized administrated

separately.

5. In this model, low grade OS like

2000/XP professional, WIN 98 etc. can be

used.

6. Users accounts are created in each PC

and are called as Local Users.

controls all other computers called clients.

3. This model is recommended for large

networks.

4. There is centralized administration and

each PC can be administrated and managed

from the server.

5. in this model high grade OS like WIN

2000/2003 Server can be used.

6. Users accounts are created on the server

side and are called Domain Users.

3.1.2 Categories of network

Networks can be categorized as per geographical area to be covered by the

network. Computer network are divided into four categories includes: Local Area

Network (LAN), Campus Area Network (CAN), Metropolitan Area Network (MAN) and

Wide Area Network (WAN).

3.1.2.1 Local Area Network (LAN)

LAN is a computer network that is used to connect computers and work station to

share data and resources such as printers or faxes. LAN is restricted to a small

area such as home, office or college. Devices used in LAN are : HUB and switch.

Media for LAN is UTP cables. Figure 1.2 shows how all work stations, server and

printer are interconnected with the help of the network device.

Fig 2: Local Area Network

Types of LAN

In LANs, data can be transferred using techniques like token passing. As per

techniques used for data sharing, LANS are classified into Ethernet, Token Bus, Token

Ring and Fiber Distributed Data Interface (FDDI).Figure 3.3 shows LAN classification.

Fig 3: LAN classification

Advantages of LAN

a). Provides communication in smaller networks, easy to install and configure.

b). many users can share data or network elements at the same time which results

in fast work.

Disadvantages of LAN

a). limited number of computers are connected in a LAN.

b). LAN cannot cover large area.

c). Network performance degrades as the number of users exceeds.

3.1.2.2 Campus Area Network (CAN)

Campus Area Network is a computer network made up of two or more LANs

within a limited area. It can cover many buildings in an area. The main feature of

CAN is that all of the computers which are connected together have some

relationship to each other e.g. different buildings in a campus can be connected

using different CAN. It will help to interconnect academic departments, library

and computer laboratories. CAN is larger than LAN but smaller than WAN.

Figure 3.4 shows a CAN network.

Fig 4: Campus Area Network

Devices used in CAN are : HUB, Switch, Layer-3 switch, Access Point .And the media

used for CAN is Unshielded twisted pair of cables and Fiber Optics Cable.

3.1.2.3 Metropolitan Area Network (MAN)

MAN is the interconnection of networks in a city. MAN is not owned by a single

organization. It act as a high speed network to allow sharing resources with in a

city. MAN can also be formed by connecting remote LANs through telephone

lines or radio links. MAN supports data and voice transmission. The best example

of MAN is cable T.V network in a city.

Fig 5 : Metropolitan Area Network

3.1.2.4 Wide Area Network (WAN)

WAN covers a wide geographical area which include multiple computers or

LANs. It connects computer networks through public networks like, telephone system,

microwave, satellite link or leased line.

Most of the WANs use leased lines for internet access as they provide faster data transfer.

WAN helps an organization to establish network between all its departments and offices

located in the same or different cities. It also enables communication between the

organization and rest world.

Devices used in WAN is only Router

3.2 IP ADDRESSES and MAC Addresses

It is also called as logical addresses. IP is a 32 bit long and it is divided into 4

octets and dot (.) is used to separate one octet from another. It is represented in the

form of decimals. There are two versions of IP addresses:

- IPv4

- IPv6

Table 2 Comparison between IPv4 and IPv6

3.2.1 IP Address Classes

IP address is a 32 bit address. It is divided into various classes namely Class A, Class

B, Class C, Class D and Class E. TCP/IP defines Class D for experimental purpose.

TCP /IP address contains two addresses embedded within one IP address; Network

address and host address as shown in figure 3.1

NETWORK

ADDRESS

HOST ADDRESS

0 bits 31 bits

IPv4 IPv6

- It is 32 bit long.

- It is divided into 4 octets.

- Ipv4 performs broadcasting,

multicasting and unicasting.

- IPv4 is divided into 5 classes:

A to E.

IPv4 is in decimal form.

- It is 128 bit long.

- It is divided into 16 octets.

- IPv6 doesn’t support

broadcasting, it performs

multicasting and unicasting.

- Ipv6 doesn’t support classes.

- IPv6 is in hexadecimal form.

Class A consists of 8-bit network ID and 24-bit host ID. Class B consists of 16-

bit network ID and 16-bit of host ID. And Class C consists of 24-bit of network

ID and 8-bit of host ID.

Address Classes

Table 3: Address Classes

`

Addres

s

Class

Starting

Bits

(first-byte)

Range of First

Octet

Mask Value Valid Hosts

Class A 0 1to 127 255.0.0.0 256*256*256-2=

16,777,214

Class B 10 128 to 191 255.255.0.0 256*256-2=65,534

Class C 110 192 to 223 255.255.255.0 256-2

Class D 1110 224 to 239 Reserved for multicasting

Class E 1111 240 to 255 Reserved for research and

development

3.2.1.1 How to Assign IP Address to Computer

An IP address assigned to a computer may either be permanent address or address

that is assigned to a computer on a time lease or for temporary basis. Hence, the address

granted to computers is divided into two categories Dynamic IP addresses and Static

addresses.

Dynamic IP Addresses

Dynamic IP addresses are assigned to the devices that require temporary

connectivity to the network or non-permanent devices such as portable computer. The

most common protocol used for assigning Dynamic IP address is DHCP also called

Dynamic Host Configuration Protocol. The DHCP grants IP address to the computer on

lease basis.

Static IP Addresses

Static IP addresses are assigned to the device on the network whose existence in

the network remains for a longer duration. These static IP addresses are semi-permanent

IP addresses which remain allocated to a specific device for longer time e.g. Server.

3.2.1.2 How to Configure IP Address in window 2003

• Right click on My Network Places- properties

• right click on working LAN card- properties

• select internet protocol (TCP/IP) -properties

• Tick on- Use the following IP addresses - now fill the IP address e.g

10.0.0.1

• Tick on –Use the following DNS server address

• Fill the preferred DNS server – 10.0.0.1

• Ok

• Close

Now check the connectivity of computer with itself with command

Start-run-cmd-ping 10.0.0.1

3.2.2 MAC Addressing

MAC address is a hardware address that is embedded in the NIC card. It is also known

as hardware address or physical address. Every NIC card has a unique MAC address

assigned by IEEE. MAC address is used to identify the nodes at lower levels of OSI

model. The MAC address operates at the data link layer of the OSI model.

MAC address is a 12 digit hexadecimal number (48 bit address). It is made up of

numbers from 0-9 or a letter from A-F. MAC address can be written in any one of the

formats:

MM:MM:MM:SS:SS:SS

MM:MM:MM:SS:SS:SS

T o identify the MAC address in window:

• Click Start →Run

• Enter cmd in the Open text book

• Type ipconfig /all

• Press Enter

The 12 digit MAC address will be shown as say 00:11:11:EA:8D:F6

3.3 NETWORKING MEDIA

To do networking we need to use some type of media. There are many types of media.

(i) Coaxial Cable

(ii) Fiber optic cable

(iii) Twisted Pair of Cables

(iv) Micro- wave

(iv) Satellite

Coaxial Cable

Coaxial cable consists of an insulated copper conductor surrounded by a tube

shaped copper braid outer copper tune and the inner conductor have the same axis of

curvature hence it called coaxial cable. It is basically of two types:

(i) Base Band Cable (RG – 59)

(ii) Broad Band Cable (RG – 58)

We used Base Band signal cable in Networking of Computers, It is so called because

it carries single frequency. Its speed is 10 Mbps and impedance is 50 Ω. Where as Broad

Band Cables carries multiple frequencies. Connector used for Coaxial cable is

BNC(British Novel Connector) connector. ARCnet uses RG-62 coaxial cable. It has an

impedance of 93 Ω and has a comparatively lesser attenuation, hence yield greater

distances. These cables are expensive and provide high propagation factor.

Fiber Optical Cable

Fiber optic cable consists of a very fine fiber made from two types of glass, one for the

inner core and the other for the outer layer. Here signal is transmitted in the form of light.

Different varieties of fiber optics is used depending on the size of the network. Single

mode fiber optics is used for networks spanning longer distance. Fiber Optics has lower

propagation factor than coaxial cable. It is a costly but more secure transmission media.

Twisted Pair Cable

There are two wires, which are twisted with each other to avoid EMI (Electro

Magnetic Induction).these cables are easy to terminate. However they have a slightly

higher value of attenuation value and hence have limited distance covering capacity.

Connector used for Twisted Pair of Cable is (Registered Jack) RJ-45 and RJ-11. There

are two types of twisted pair of cables:

• STP (Shielded Twisted Pair):

In this an extra wire which is called shielded wire is wrapped over the inner

cover which holds copper in pairs. This protection is used to protect signal from

external noise.

• UTP (Unshielded Twisted Pair)

In this type of wire no shielded cover is there for extra protection from noise.

There are different categories of UTP cables:

Categories of UTP Cables

Table 4: Category and Speed of UTP cables

Category Speed

CAT-1

CAT-2

CAT-3

CAT-4

CAT-5

CAT-6

CAT-7

56 Kbps

4 Mbps

10 Mbps

16-20 Mbps

100 Mbps

1Gbps

1Gbps

3.3.1 Ethernet Cabling

There are three types of Ethernet cables:

• Straight cable

• Crossover cable

• Rolled cable

3.3.1.1 Straight cable

It is used when we have to connect

• PC TO Switch

• PC to Hub

• Hub to Router

• Switch to Router

Colour Coding for straight Cable

TABLE 5

568A

(one end) (other end)

568B

(one end) (other end)

Green/white

Green

Orange/white

Blue

Blue/white

Orange

Brown/white

Brown

Green/white

Green

Orange/white

Blue

Blue/white

Orange

Brown/white

Brown

Orange/white

Orange

Green/white

Blue

Blue/white

Green

Brown/white

Brown

Orange/white

Orange

Green/white

Blue

Blue/white

Green

Brown/white

Brown

3.3.1.2 Crossover Cable

It is used when we have to connect:

• PC to PC

• Hub to Hub

• Switch to switch

• Router to Router

• PC to Router

• Hub to Switch

Colour Coding for Crossover cable

Table 6 Colour Coding for Crossover cable

(one end) (other end)

Orange/white

Orange

Green/white

Blue

Blue/white

Green

Brown/white

Brown

Green/white

Green

Orange/white

Blue

Blue/white

Green

Brown/white

Brown

3.3.1.3 Rollover Cable

Rollover cable isn’t used to connect any Ethernet connections together, but

Rollover cable can be used to connect a host to a router console serial communication

(com) port.

NOTE: Straight cable and Cross cables are used for data transfer but Rollover

cables are not used for data transfer.

There are two methods for manufacturing Rollover cables:

Table 7 Colour Coding for Rollover Cable

568A

(one end) (other end)

568B

(one end) (other end)

Green/white

Green

Orange/white

Blue

Blue/white

Orange

Brown/white

Brown

Brown

Brown/white

Orange

Blue/white

Blue

Orange/white

Green

Green/white

Orange/white

Orange

Green/white

Blue

Blue/white

Green

Brown/white

Brown

Brown

Brown/white

Green

Blue/white

Blue

Green/white

Orange

Orange/white

3.4 OPERATING SYSTEM

3.4.1 Types of Operating Systems

(i) DOS (Desktop Operating System) (ii) NOS (Network Operating System)

Table 8: Operating Systems

DOS

1. It is a desktop operating system.

2. It is used in small networks.

3. In this OS, there is less security.

4. In this OS, all computers are clients.

5. In this OS, MS-DOS, GUI package

Win

3.1, Win 95, Win 98, Win ME comes.

NOS

1. It is a network operating system.

2. It is used for large networks.

3. In this OS, there is more security.

4. In this OS, there are servers and

clients.

5. In this OS Win NT, Win 2000, Win

2003, LINUX, UNIX, Novell and

MAC comes.

3.4.1.1 Introduction to Window 2003 Server

Window server 2003 (also referred to as WIN 2k3) is a server operating system produced

by Microsoft. Introduced in 24th April 2003 as the successor to window 2000 server, it is

considered by Microsoft to be the corner stone of its window server system line of

business server products. An update version Window Server 2003 R2 was released

manufacturing on 6th dec, 2005. its successor window 2008 was released on 4th feb, 2008.

According to Microsoft, window server 2003 is more scalable and deliver better

performance than its predecessor window 2000.

Features of Window 2003

(i) A significant improved version of Internet Information Service (IIS)

(ii) Increased default security over previous version due to the built in firewall

and having most services disabled by default.

(iii) Manage your server-a role management administrative tools that allow an

administrator to choose what functionality the server should provide.

(iv) Improvement to Active Directory.

(v) Improvement to Group Policy handling and Administration.

(vi) Provides a Backup system to restore lost files.

(vii) Improved disk management, including the ability to Backup from shadows of

files, allowing the Backup of open files.

(viii) Improved security and command line tools which are part of Microsoft

initiative to bring a complete command shell to the next version of window.

(ix) Support for a hard based “Watch Dog Timer”, which can restart the server if

the operating system does not suspend with in a certain amount of time.

Removed Features

• The ability of creating server disk automated system recovery (ASR) is used

instead .

Edition of Window 2003

Window server 2003 comes in a number of editions, each targeted towards a

particular size and type of business. In general, all variant of window server 2003

have the ability to share files and printers, act as application server and host

message queue, provide email services, authenticate users, act as an X.509

certificate server, provide LDAP (Light Weight Directory Access Protocol)

services, serve streaming media, and to perform other server-oriented functions.

3.5 DNS SERVER

DNS stands for domain name system. DNS system is a standard technology

for managing the names of websites and other internet domains. DNS techniques allows

you to type names into your web browser like computer networking, about computer and

allow your computer to automatically find that address on internet. DNS is the resolution

mechanism used by Window Server 2003 clients to find other computers and services

running on those computers for computers in a window 2003 network infrastructure to

talk to one another, one of the key ingredients is the DNS server .Host name alone do not

communicate globally but communicate locally, but if domain name is added along with

it then the host name can communicate globally. DNS is use for name reservation i.e. to

convert IP address to host name and host name to IP address or the function of DNS is to

resolve host name such as www.yahoo.com to an IP address. User identify only user

friendly name and all computers and technologies identify IP address and MAC address

DNS is use to solve this problem because DNS is used to convert host name FQDN (fully

qualified domain name) to IP address and IP address to host name .

3.5.1 PARTS OF DNS SYSTEM

(i) Host name

(ii) Domain name

(iii) FQDN

(iv) Namespace

(v) DNS server

3.5.1.1 HOST NAME

Host name is a computer name and is also called is NetBIOS (network basic

Input/ output system) name. NetBIOS is actually an application layer protocol that can

use the transport services of TCP/ IP when used in routed network. A NetBIOS name is

16- byte addresses that identify a NetBIOS resource on the network.

3.5.1.2 DOMAIN NAME

Domain name is used to identifies the internet site one can identifies the location

without having to remember the IP address of every location e.g. yahoo.com or

gmail.com

3.5.1.3 FQD

FQDN means fully qualified domain name which represents a hostname appended to the

parent name space in hierarchy. Also in fully qualified domain name different levels of

namespace are visualize as in fig below this hierarchy is visualized the root level

namespace, top level domain, and so on, in use throughout the internet today. Left most

portion of the FQDN is the host portion of the name. A host name is alias we give to an

IP address.

Fig 6:To find location of a computer using FQDN

FQDN is a unique name in the computer on the network. We can identify host id and

location of a computer as in fig above. Suppose we want to find location of pc1 with

IP address 20.0.0.1, which is in lab2, 2nd floor in the organization center. The FQDN

for this is

Pc1.row3.lab2.floor2.center.com

But this address is very lengthy to locate pc1 so to simplify this we use “c name”

technique as:

Pc1.center.com=20.0.0.1

3.5.1.4 Domain Namespace

DNS operates in what is known as DNS namespace. The DNS namespace is an

organized, hierarchical division of DNS names. Domain namespace enable users to easily

locate the network services and resources. The domain namespace include the root

domain, the top level domain of the organization and organize these domain in a

hierarchical tree structure. Namespace works on the hierarchical tree structure of root

domain. There are total 13 root domain working in the internet, they are A, B, C, D, E, F,

G, H, I, J, K, L and M. There is one root domain, which acts as the starting point of the

fully qualified domain names. This root domain is designated with a dot (.). Fig 6.2

shows the tree structure or domain namespace.

Fig 7: Tree structure or Domain Namespace

3.5.1.5 DNS server

Any computer providing domain namespace is a DNS server. DNS server is used to

convert host name FQDN into IP address and IP address into host name FQDN. To store

the name-to-IP-addresses mappings so crucial to network communication, name server

uses zone files.

3.5.2 DNS Zone

Zone is the part of DNS database that contain record of domain or multiple domain.

If the domains represents logical division of the DNS namespace, zones represents the

physical separation of the DNS namespace. In other words information about records of

the resources within DNS domain is stored in a zone files, and this zone files exist on

hard drive of server. Zone files are divided into one of two basic types:

• Forward lookup zone: Provides host-name-to-IP-address resolution

• Reverse lookup zone: Provides IP-address-to-host-name resolution

3.5.2.1 Resource record stored in a zone file

Each record stored in a zone file has a specific purpose. Some of the records set the

behavior of the name server, others have the job of resolving a host name or service into

an IP table.

(i) NS (Name Server):

These specify the name servers that are authoritative for a given portion

of DNS namespace. These records are essential when DNS servers are performing

iterative queries to perform name resolution.

(ii) SOA (Start of Authority):

This resource record indicates the name of origin for the zone contains the name

of the server that is the primary source for information about the zone. The information in

an SOA record affect how often transfer of the zone are done between servers

authoritative for the zone. It is also used to store other properties such as version

information and timings that affect zone renewal or expiration.

(iii) CNAME (Canonical Name):

CNAME can be used to assign multiple names of a single IP address.

For example, the server hosting the site www.abc.com is probably not named www, but a

CNAME record exist resolution of www to an IP address all the same. The CNAME

record actually points not to an IP address, but to an existing A record in the zone.

3.5.2.2 Steps to Install and configure DNS server

• Start → control panel→ add and remove program

• Add remove window components

• Select networking services and click on detail button

• Check box of DNS server

• Ok and finish

3.5.2.3 Creating a Forward Lookup Zone

• Statically fill the IP address

• Start →administrator tools

• DNS→ right click on forward lookup zone

• New zone→ next

• Select primary zone→ next

• Enter zone name (abc.com)→ next

• Tick Allow both secure and non secure updates and secure dynamic

updated

• next→ next

• now click on created zone (abc.com)

• new host→ enter host name for global level (i.e by entering www) fill IP

address of the web server , click on add button

• enter another host name, a blank host with same IP i.e do not fill its host name

steps to change SOA and NS records

• Right click on SOA records → properties

• Fill primary server e.g (www.abc.com)→ responsible person

• host master.abc.com→ apply→ ok

• right click on NS records

• click on add button→ enter FQDN→ www.abc.com

• resolve→ ok→ apply→ ok

Now go to start menu → ping abc.com

On Client Side → To access DNS server fill IP address of server then use ping command

e.g ping www.abc.com

3.5.2.3 Creating a Reverse Lookup Zone

• Right click on reverse lookup zone

• New zone→ next→ select primary zone→ next

• fill →Network ID→ next→ next

• Select allow both non secure and non secure dynamic updates

• Finish

• Right click on created reverse zone→ new pointer

• enter host IP number e.g (50.0.0.50)

• enter FQDN (www.chd.com)

3.5.2.4 Some DNS Commands

(i) c:>tracert www.yahoo.com

command is used to check the path , a data packet follow from one router

to another router.

(ii) c:>nslookup

command display the domain name with IP (works only when reverse lookup

zone is set up).

(iv) c:>ipconfig /all

This command display FQDN, IP address, MAC address.

(iv) c:>ipconfig /flushdns

This command flush or clear all the information in the cache that is retrieved

from DNS server.

(v) c:>ipconfig /displaydns

Display the current contents or entries in the cache.

(vi) c:>ip config /register

register any DNS name

3.6 DHCP SERVER

DHCP (Dynamic Host Configuration Protocol) is a protocol that allocates IP address to

computer on a network. DHCP centralized the management of IP address allocation and

reduces human error associated with manual IP configuration. DHCP server supplies all

the necessary networking param-eters. Two things are always handed out as a part of

DHCP configuration: IP address and subnet mask. Further DHCP will frequently

configure clients with optional values, such as a default gateway, DNS server address,

and the address of a Window Internet Naming Server, if one is present. Scenario showing

DHCP server IP address allocation.

3.6.1 Working of DHCP Server

(i) DHCP Scope

(ii) DHCP Super Scope

(iii) Exclusion IP Range

(iv) DHCP Lease Time

(v) IP Reservation

DHCP Scope

Scope having the range of IP address for providing dynamic IP address to other

computer. A group of IP address within a scope is called as DHCP scope.

DHCP Super Scope

A super scope is used to combine two or more scopes each serving different subnets, and

can make the administration of several scopes on window 2003 DHCP server more

manageable. Using super scope you can group multiple scopes as a single administrative

entity that allows the client to lease from either one. With this feature, a DHCP server

can:

• Support DHCP clients on a single physical network segment where multiple

logical IP networks are used. When more than one logical IP network is used on

each physical subnet or network, such configuration is called multinets.

• Support DHCP clients located on the far side of DHCP and BOOTP relay agent.

• In multinet configuration, DHCP superscope can be used to group and activate

individual scope ranges of IP addresses used on your network. In this way , a

DHCP server computer can activate and provide leases from more than one scope

to clients on a single physical network.

Exclusion IP range

If you want to reserve some IP for any computer i.e if we want that from the series of

192.168.0.2 to 192.168.0.100 if we want that a series of IP addresses must not be

assigned automatically then at can be done using exclusive IP range.

DHCP Leased Time

DHCP lease time is validity of IP address. By default DHCP lease time is 8 days

minimum,1 day maximum 999 days, 23 hours to53 day.

With in 8 days:-

After 80% of day clients demand new IP some times server refuse the client request.

After 87.5% of days it will retry, and if the server did not give the new IP address then

the client will receive APIPA address (Automatic Private IP Address).

When a DHCP client is unable to locate a DHCP server, the client picks out a random IP

address from the private APIPA address range of 169.254.*.*, with a subnet mask of

255.255.0.0. The 169.254.*.* IP range is private because that network number is not in

use on the internet, it is random because the client generates an arbitrary host number for

that network.

The significance of APIPA is that DHCP client computers that cannot find a

DHCP server can still be assigned an IP address and communicate with other computers

on the same subnet mask that also cannot find DHCP server. It allows communication

when DHCP server is down or just plain not there. Note that APIPA does not assign a

default gateway, and therefore it cannot communicate with any computer that lives on the

other side of a router.

IP Reservation

There are some DHCP clients that you want to be the DHCP clients, but you will also

want to make sure that they get same IP address every time. This can be done by

statically filling the IP address. We can reserve IP address with the help of MAC address

for a particular computer.

3.6.2 Installation Steps of DHCP Server

• start→ control panel

• add and remove program→ add and remove window components

• select networking services and click on detail button

• check box of DHCP server

• ok→ finish

3.6.2.1 Steps To Configure DHCP Server

• start→ program→ administrative tool

• select DHCP

• create new scope in action menu→ new scope → next

• give scope name→ next

• give IP address range→ next

• add exclusion name→ next

• check lease duration→ next→ finish

After DHCP server is configured, it is required to be authorized and DHCP scope

should be active. For that select DHCP server and click on authorize in action menu.

Then right click on scope name and click on active.

3.6.2.2 On Client Side

• Go to LAN card properties → select TCP/IP protocol→ properties

• Select obtain IP address automatically

• Go to command prompt (cmd)

• Give command

3.6.2.3 Backup of DHCP Server

We can take backup of all the configuration in DHCP server with the help of

administrator. Backup means to export the DHCP database to another system, as it is

helpful in case due to any reason our data is corrupted or deleted, we can take our

database from the place where it is stored. Steps of taking backup :

• Stop the DHCP server and disable the DHCP server services

• Copy the DHCP server directory to a temporary location, say pen drive or

on a new DHCP server.

3.6.3 DHCP Relay Agent

The DHCP relay agent is a software that listen DHCP discover packet and forward to

DHCP server. In window 2003 server system the DHCP relay agent can be enabled as a

part of Routing and Remote Access (RRAS).

3.6.3.1 Steps To Configure DHCP Relay Agent

• Set the network, fill the IP address and select two LAN cards

• Open Routing and Remote Access → enable Routing and Remote Access

• Right click on general new routing protocols

• Select DHCP relay agent

• New interface

• Select LAN card which is to be connected to the cross cable i.e L1

• Ok

• Right click on relay agent → properties

• Enter IP address of DHCP server

• add→ apply→ ok

3.7 ACTIVE DIRECTORY

With the release of Windows 2000, Microsoft introduced Active Directory, a scalable,

robust directory service. Active Directory is used to create server based networking.

Active Directory’s job is to store and make available a Directory database i.e information

about the user, its class, name, address, mails, phone numbers, location.

Active Directory is a technology created by Microsoft that provides a variety of

network services like Directory Services, DNS based naming and other network

information. Active Directory also allows administrator to assign policies, deploy

software and apply critical updates to an organizations. Active Directory was previewed

in 1999, released first with window 2000 server edition and revised to extend functionally

and improve administration in Window 2003. Additional improvements were made in

Window server 2003 and Window server 2008.

The fundamental building block of Microsoft’s Directory services continues to be a

domain. A domain is logically grouping of network resources, including shares, printers,

groups and users accounts. The user account represents the individual to domain, and

allows for different type of access and different types of tasks. Every users account is

unique. It has uniqueness of the user account that allows administrator to control access

for every member of domain.

There are two types of users accounts: local account and domain account. Local

accounts are maintained in the local database of a computer and cannot be used to grant

access to network resources. Local users are primarily used to administer a computer or

to allow several people to share a single computer that is not a member of a domain.

Whereas domain users accounts are much more widely used in organizations that local

user accounts because they allow for central administration and user can log onto any

computer in the domain. Domain users accounts are stored in Active Directory.

3.7.1 Active Directory Services

A computer network can be divided logically into two networking models.

• Workgroup

• Domain

Difference Between Workgroup and Domain

Table 9

Workgroup Domain

1. It is a peer-to-peer networking

model.

2. There is no client and no server.

All computers are in equal status.

3.This model is recommended for

small networks (upto 10 pcs).

4. There is no centralized Admin-

istration and each PC is

administrated separately.

5.In this model, low grade operating

system like 2000/xp professional,

win 98 etc can be used.

6. Workgroup can be given names

like sales, HR, accounts etc.

1. It is a server based networking model.

2.there is a centralized dedicated server

computer called domain controller

(DC)which controls all other computers

called clients.

3. This model is recommended for large

networks.

4. There is centralized administration

and each PC can be administrated and

managed from the server.

5.In this model high grade operating

system ,like win2000/2003 server are

used.

6. Domain can also given names like

abc.com, xyz.com etc.

7 Users accounts are created in each

PC and are called as “Local Users”. 7.Users accounts are created on sever

side DC and are called as ”Domain

Users”.

Active Directory uses domain to hold objects, each domain has security boundary.

Users must authenticates to the domain in which their users account resides before they

can access resources, such as a shared folders. Active Directory also links related

domains in a hierarchical structure and users can access resources in any of the domain in

which their user account resides. The hierarchical structures of related domain is called a

tree, and all domains in the tree share the same Domain Name System (DNS) namespace.

All the domains and the trees in a single organization are called a forest. All domains in

the forest share same schema.

3.7.1.1 Types of Domain

• Domain Forest

• Domain Tree

• Organization unit

Domain Forest

A forest is created when window 2k3 server computer is configured as a domain

controller. A forest is a collection of multiple domain link together and relationship

between the domains.

Domain Tree

A domain tree is made up when there is a parent child relationship between the domain

in the forest. The child domain includes the complete parent domain name. a tree is a set

of two or more domains sharing common namespace e.g we can create a parent domain

and then child domain like mail.yahoo.com; where mail- child domain, yahoo- parent

domain.

Fig 8: Structure of domain forest and domain tree

Organization Unit (OU)

Organization unit is the smallest unit in a domain network that can contain users,

computer groups, shared folders, printers and group policy object in simple words. OU

means department like sale department, accounts department like sales, accounts in a

company OU can be used to apply different security policies to computer and users in

different department. OU also helps in dividing administration among different

administrator of managing only computer and users of sales department.

3.7.1.2 Types of Domain Controller

(i) PDC : Primary domain controller

(ii) ADC : Additional domain controller

(iii) BDC : Backup domain controller

Primary Domain Controller (PDC)

This is the first domain controller, in this domain all entries are created in it like

users account, group policy, Organization unit etc. All FSMO role are done in PDC.

Additional Domain Controller (ADC)

It is a domain network, it is important to have more than one DC so that if one

DC fails, the other DC will continue serving the client. There is also load balancing of

Active Directory Service if we have more than one DC.

The first DC we create is simply called PDC and if we create an extra DC then

that DC is known as ADC. ADC has same configuration of AD as primary domain

controller.

All domain controllers in a domain networking are masters. We can make a

change in the active directory of any domain controller and that change is replicated to all

other domain controllers. Replication takes place among all the domain controllers and it

is controlled automatically. If we create a user in the first domain controller, it is

automatically created in the ADC because of replication.

All the domain controllers in the domain networking are peers and this model is

called as multi- master model .

Fig 9: Multi-Master Model

3.7.1.3 Requirements of Active Directory

(i) Window 2000/2003 server computer.

(ii) Atleast one NTFS partition.

(iii) Static IP address

(iv) Atleast 1GB free hard disk space

(v) LAN card enabled and connected to the network

(vi) Install DNS, if not installed of Active Directory and configure it.

It should be noted that active directory cannot work without DNS.DNS is

automatically installed and configured during the Active Directory installation.

3.7.1.4 Installation of Active Directory

First of all fill the static IP address, then install DNS service into it and after that

install the Active Directory

• start→ run→ dcpromo

• Ok

• Welcome to active directory → next→ next

• Select domain controller for a new domain e.g (gmail.com)

• Next

• Domain NETBIOS name (gmail.com)

• Next

• Data folder, folder new tech directory service→ next (SYS VOL)

• Next

• Click on install and configure the DNS server on this computer to use this

DNS server as its preferred DNS server.

• Tick on permission compatible only with window server

• Next

• Enter the restore mode and the password

• next→ next→ finish

• now restart computer

Command used for the removal of Active Directory

start→ run→ dcpromo

This command is also used to remove active directory, if after this command the

active directory is not removed then type

• start→run

• cmd→dcpromo /forceremoval

• Ok

How to identify Active Directory installation

• Start → administrator tool

After that if three options specified if come, it means that Active Directory

has been installed

Active Directory domain and trusts

Active Directory sites and services

Active Directory users and computer

Open DNS console by

• Administrator tools→DNS

• Forward lookup zone

msdcs.exam.edu

start of authority (SOA)

name server (NS)

Now ping active directory with domain name like

• start→ run→ ping gmail.com

Backup of Active Director

Active Directory backup come in use when there is some problem in active directory. If

there is any problem in active directory then remove it and restore the backup.

• Start→ run→ntbackup→ok

• Select advance mode and untick that is already ticked

• Select backup

• Selsct system state

• Change backup path browse keep in your hardware and then send it to the

pen drive

• D:\adbackup

3.7.2 CHILD DOMAIN

A domain is created say “xyz.com”. this domain is known as parent domain or the

root domain. Now “chd.xyz.com” will be the child domain or the sub domain of xyz.com.

Fig 10 : parent-child relationship model

A child domain is created to ease administration in a very large domain network. We can

create the parent domain in the head office of the company and the child domain in the

branch offices.

Each branch office will have its own administrator to manage the users of the

child domain present in the branch office.

A true relationship is automatically created between the parent domain and the

child domain. This means users in the child domain can access the file server of the

parent domain. Moreover users of either domain can use clients of either domain for

logging in the domain but a user can always logon only in the domain in which his

account resides, though he physically can use client pc of parent or client domain. Users

of either domain can logon its own domain from either side but only when it use its own

domain name. users of parent domain can communicate with child domain but he has to

use its domain name for that.

3.7.2.1 Steps to create child domain

First of all install the active directory on pc1 i.e on the parent domain. Now make Tom

user on it. On pc2 create the child domain, then make users on it, user- Ram

Below are the steps to cerate child domain.

• Fill the IP address in the child domain

• Now ping to the parent domain with the domain name (xyz.com)

• Run →dcpromo→ ok

• next→ select domain controller for a new domain

• next→ select child domain and existing domain name (mcse.com)

• next

• enter username, password and domain name

• enter user parent domain name also enter child domain name

• enter complete DNS name i.e xyz.mcse.com

• next→ next→ next→ next

it should be noted that parent domain can logon into child domain but on the other

hand child domain cannot logon to the parent domain. Also parent domain can apply

policies or security on the child domain.

Make the client member by entering particular user with its domain name.

• First right click on My Computer

• Properties

• Computer name

• Change

• Write domain name →ok

Now logoff start and then write user name - Tom

Domain name - mcse.com

Again logoff and check the other user

Start-user name- abc

Domain name – mail.mcse.com

3.8 INTERNET SHAREING

We can share a single internet connection to multiple computers with the help of

networking or internet sharing. There are four ways to share internet.

(i) Direct sharing

(ii) ICS – Internet connection sharing

(iii) Win Proxy

(iv) NAT – Network Address Translation

3.8.1 Direct Sharing

Internet sharing can be done between computers directly, just by taking internet

connection directly from ISP (Internet Server provider), then it is provided to ADSL

model, ADSL modem is connected to the ISP through RJ-11 connector. Then it is

connected to the switch with RJ-45 connector. Switch, further connects computers those

have to be provided with internet connection. The scenario for direct sharing is as shown

in figure:

Fig: 11: Direct Sharing Scenario

ADSL modem has IP address 192.168.1.1. All the PCs are assigned with a DNS

(Domain Name Server) and GW (gateway) -192.168.1.1. Also DHCP (Dynamic Host

Communication Protocol) is enabled which will provide IP addresses to the PCs

automatically.

3.8.2 ICS (Internet Connection Sharing)

Internet Connection sharing provides an alternate way to provide Internet Sharing.

ICS requires a server with two network interfaces, one for the private internal network

configured with IP 192.168.0.1 address and an adapter for public connection. ICS

requires two connections in order to work: one public and one private i.e. ICS server

requires two LAN cards, Internal (Private) and External (Public). Internal LAN card uses

Local LAN card (L2) and External LAN card (L1) is used by Internet. ICS is designed to

be as simple as possible. ICS works on following windows: XP, Vista, 2K3 Server, 2k3

Server SP1.it doesn’t work on the server in which AD+SP1 is present. The scenario for

ICS is shown below:

Fig 12: ICS scenario

Note:- When we configure ICS then the local card detect 192.168.0.1 address

automatically.

How to configure ICS

• Open network and sharing center

• Network- Properties

• Click on Manage network connections

• Right click on LAN Card which is used for internet- Properties

• Click on sharing

• Enable ICS

• Ok

• yes

3.8.3 Win Proxy Server

Win Proxy is a third party software which is used for sharing internet and we can

also block the web site with the help of win proxy. WIN Proxy supports all the three

classes A, B, C also it is supported by all operating systems. The scenario for WIN proxy

is shown below:

Fig 13: scenario of win proxy server

In win proxy as shown in the scenario above we can share internet. First of all a ADSL

modem is connected to the ISP (Internet Service Provider) by a RJ-11 connector and

other end of ADSL modem is connected to the PC1 through RJ-45. Assign IP address

192.168.1.1 to the ADSL modem also enable the DHCP server and set the start IP

address of 192.168.1.2 and end IP address of 192.168.1.254. Then after ADSL modem

connect PC1, assign GW 192.168.1.1 and

3.8.4 NAT (Network Address Translation)

If we have to connect many computers with a single IP address then we will use NAT.

NAT exchange IP packet between local network and internet. The routing and remote

access server of window 2K3 server provide us with a component known as NAT. By

enabling NAT on a Server 2003 system, you allow connected users on a private system to

share a single connection to access a public network such as the internet i.e. NAT enable

multiple client computer to connect the internet through a single publicly registered IP

address. A NAT server translate private IP address to public addresses. NAT eliminates

the need for large number of IP addresses by mapping externally assigned IP addresses.

Fig 14: NAT server

When deploying NAT, it is needed to configure setting on both the client side

and the server side. On the server side of NAT fill the IP address statically.

3.8.4.1 Steps to enable NAT server

• Open internet → Tools→ Internet options

• connections→ LAN settings

• untick the IP and port address

• ok→ ok→ give site name

. On the client side of NAT, client side is configured to obtain IP addresses

automatically and then restart the client system. Assuming NAT is used for address

assignment, the client system will receive TCP/IP information from the NAT server. The

client information includes:

• IP address from 192.168.0.0 private addressing range

• Subnet mask (255.255.255.0)

• DNS server address, which would be the address of the NAT interface

on the server.

With the client side configured, there are few things to do on NAT server:

The first step to configure NAT server is to actually install the Routing and Remote

Access Services. To do this, start the Routing and Remote Access Service Setup Wizard.

• Start→ administrator tools→ Routing & Remote Access

• Right click on My Computer→ right click on computer name

• Select option Configure and enable routing & remote access

• Welcome to routing → next→ next

• Select NAT→ next

• Select LAN card which is to be connected to internet

• next→ next

From any of the four methods of internet sharing only method is used at a

time to remove the other method

• go to start→ setting

• add & remove

• change/ remove, tick on remove.

3.9 VIRTUAL PRIVATE NETWORK (VPN)

A virtual private network is used to convert public network address to private

network. All the clients of VPN dial to public IP address of VPN server and receive

private IP from virtual VPN dynamic host protocol (DHCP).in VPN one can have

multiple virtual connections to a single IP address. This way ,one network card can host

several inbound connections, rather than require a modem and telephone line for each

simultaneous remote user.

Fig 15 : scenario of VPN server

Using VPN server we can connect many private networks to internet services i.e the

remote connection. We can create a private network through public network, we can use

firewall for security and data encryption in VPN server.

3.9.1 VPN components

(i) VPN server

(ii) VPN Clients

(iii) WAN Option

(iv) Security Options

VPN Server

VPN server, serve as the end points of a VPN connection. When configuring a

VPN server, you can allow access to just that server, or pass traffic through VPN server

so that the remote user gain access the resources of the entire network.

VPN Client

VPN clients establish connection to VPN server. They can also be routers that

obtain the router-to-router secure connection. VPN client software is included in all the

modern window operating systems, including Window 2003 server. Router-to router

VPN connection can be made from computers running server2003 and Windows 2000

running Routing and Remote Access. Additionally, any client that support PPTP or

L2TP connections can be VPN clients of a window server 2003 system.

WAN Options

These provide the physical mechanism for passing data back and forth. These

connections typically include such similar network technologies such as T1or frame

relay. In order for VPN connections to be successful, the VPN client and VPN server

must be connected to each other using either permanent WAN connection or by dialing

into an internet server provider (ISP).

Security Options

Since a VPN uses a network that is generally open to the public, it is important

that the data passed over the connection remain secure. To aid with secure

communication routing and remote access supports such security measure as logon and

domain security, data encryption, smart cards, IP packet filtering and caller ID.

3.9.2 Types of VPN

(i) PPTP (Point to Point Tunneling Protocol )

(ii) L2TP (Layer 2 Tunneling Protocol) according to CCNA.

Point to Point Tunneling Protocol (PPTP)

PPTP is Microsoft’s legacy protocol for supporting VPN. It was developed in

conjunction with other communications companies such as Robotics as an extension to

the PPP protocol. PPTP encapsulates IP or IPX packets inside of PPP datagram’s. This

means that you can remotely run programs that are dependent upon particular network

protocols. One of the keys to remember about PPTP is that the protocol provides

encryption capabilities, making it much safer to send information over nonsecure

networks.

Layer Two Tunneling Protocol (L2TP)

L2TP is a standard based encapsulation protocol with roughly the same

functionality as a Point-to-Point Tunneling Protocol (PPTP). One of the key differences

between Window’s server 2003 implementation of L2TPand it cousin PPTP is that

L2TPis designed to run natively over IP networks only. This implementation of L2TP

does not support native tunneling over X.25, frame relay, or ATM networks. Like PPTP,

L2TPencapsulates Point-to-Point Protocol (PPP) frames, which then encapsulate IP or

IPX protocols, allowing users to remotely run programs that are dependent on specific

network protocols . But unlike the PPTP protocol, L2TP does not provide encryption of

the data. For data security L2TPrelies on the services of another standards- based

protocol, IPSec.

3.9.3 How to configure VPN

• start→administrative tools

• Routing and Remote access

• Right click on computer name configure and enable Routing and Remote

access

• next→ select remote access (dial up or VPN)

• next→ VPN→ next

• select LAN card which is connected to internet (172.15.15.50) public IP

• disable enable security → next

• from a specific range of address→ next→new

• enter the required range

• ok→next→ no radius

• next→ finish

3.9.4 Create users in VPN server

• open user properties→ dial in → allow access

• apply→ ok

3.9.5 Working on Client Side

• Right click on My Network Places→ properties

• Double click on New Network Wizard→ next

• Connect to network at my work place→ next

• Virtual private network connection→ next

• Enter company name (abc)→ next

• Enter public IP address of VPN server→ next

• Any one use →next

• finish

3.10 ROUTING

It is a process of transferring information through an inter network i.e from one

network to another. Routing connect different networks having ID help in process of

routing. The dial-in properties also allow for specific IP address to be assigned to a user.

This is the only way in Window Server 2003 that you can assign a specific IP to a user.

To assign a specific IP to a user, check the box next to assign A Static IP Address and

enter a valid IP in the space provided. Static routing can also be specified as per user. By

defining static routes, users can be limited to only specific parts of networks.

In an internetwork a router must then about all the networks present in the for

effort websites, there are hardware routers like CISCO. Even win 2003 server computer

configured as router. In simple words Router is a computer with two network cards.

These two network cards, then, are attached to two different logical IP networks. The

routing table helps direct traffic that is passed through the router.

Now when there is a router, also there is a routing table, there is a need to

configure the router in order for that router to pass along traffic to the proper network.

There are two ways the routing table can be built and modified: either manually or

automatically.

3.10.1 Types of Routing

(i) Static Routing

(ii) Dynamic Routing

3.10.1.1 Static Routing

In this routing information required for routing is manually entered into the router

by administrator.

How to configure LAN routing

• Enter the static IP in the router

• Administrator tools

• Routing and Remote access

• Right click on computer name (pcc1)

• Configure and enable routing and remote access

• next→ custom configuration

• select LAN routing→next→ finish

• yes and logon to see IP table route

Enable LAN routing enable LAN routingInterface WAN Interface WAN 10.0.0.0IP 172.15.0.0 IP 10.0.0.0SNM 255.255.0.0 SNM 255.0.0.0GW 20.0.0.2 GW 20.0.0.1

Fig 16 : scenario for LAN routing

How to configure static routing

At Router R1:

• enable LAN routing

• right click on static route

• interface WAN

• destination 172.15.0.0

• mask 255.255.0.0

• GW 20.0.0.2

At Router R2:

• Enable LAN routing

• Right click on static route

• Interface WAN

• Destination 10.0.0.0

• Mask 255.0.0.0

• GW 20.0.0.1

Fig 17 : static routing

3.10.1.2 Dynamic Routing

The other way to manage a router routing tables is to let the computer do it

for you. Just like DHCP allocate IP addresses, configuring the dynamic routing

protocol usually means less errors due to human error, and less administrative

overhead.

In dynamic routing, routing information is automatically entered in the

router using protocols like RIP AND OSPF. These routing protocols used by

Window Server 2003 use one of two kinds of algorithms to determine the best

possible path for a packet to get to its destination, either distance vector or link

state. RIP is used for small networks where as OSPF is used for large networks.

Routing Information Protocol (RIP)

The distance vector protocol in use on Window 2003 is called Routing

Information Protocol (RIP) for IP. This protocol was designed for the exchange of

the routing information within a small to medium size IP network.

When Router is enabled on Window 2003 machine, the routing table includes

entries only for the networks that are physically connected. When RIP is enabled

for an interface, the router will periodically send an announcement of its routing

table to inform other RIP routers of the networks it can reach. RIP version1 uses

broadcast packets for its announcement. RIP version2 offers an improvement and

can be configured to use either multicast or broadcast packets when

communicating with other routers. Also, RIP version2 offers more flexibility in

subnetted and classless inter domain routing (CIDR) environments.

The biggest advantage of RIPis its simplicity. With a few clicks in the Routing

and Remote Access Server and MMC console, you can deploy RIP. With the RIP

dynamic routing protocol installed on Window’s Server 2003, you get the

following features:

(i) RIP version1 and version2, with the ability to configure individual

network cards with separate versions.

(ii) Calculations used to avoid routing loops and speed recovery of the

network whenever topology changes occur.

(iii) Route filters; you can configure RIP to except information from

only certain networks, and also choose which routes will be shared

with RIP routers.

(iv) Peer filters, which allow control over which router announcements

are accepted.

(v) Simple password authentication support.

But there are significant drawbacks, which makes RIP a poor, if not unusable

solution for large networks. For example, the maximum hop count used for RIP routers

is15, making network 16 hops away (or more) unreachable where RIP is concerned.

Open Shortest Path First (OSPF)

Where RIP is built to work to work in smaller networks, the Open Shortest Path

First (OSPF) routing protocol is designed for large or very large networks. The goal is the

same: information about connection to other networks is shared from one router to

another. It offers several advantages over RIP, especially significant in large networks:

(i) Routes calculated with OSPF are always loop free.

(ii) OSPF can scale much more easily than RIP.

(iii) Reconfiguration for network topology changes is faster.

The biggest reason OSPF is the choice in large networks is its efficiency; instead

of changing routing table via broadcast the way RIP does, OSPF configured routers

maintain a map of the network. The mapping is called the link state database, OSPF

routers keep the link state database up to date. Once changes have been made to link state

database, an OSPF router’s link state database is recalculated.

As the networks start to multiply, the size of the link state database increases, and

a corresponding hit on router performance results. To combat this, OSPF sub divide the

network into smaller sections, called areas. Areas are connected to each other through a

backbone area, with each router only responsible for the link state database for those

areas connected to the routers. Area Border Routers (ABRs) then connect one backbone

area to another.

The biggest drawback of OSPF is its complexity; OSPF requires proper planning

and is more difficult to configure and administer.

3.11 EXCHANGE SERVER

Exchange server is a mail server, we can send and receive mail from one user to another

user. Exchange server is the mail server of Microsoft.

3.11.1 Elements of Exchange Server

Mail Server

A server which helps to the users to send and receive mail is called mail server.

Mail Box

A storage place where senders and receivers mails are stored.

3.11.2 Exchange Version

Table 10: Exchange Server with different operating systems

Exchange Version Operating System

Exchange Server 5.5

Exchange Server 2000

Exchange Server 2003

Exchange server 2007

WIN NT or 2000 server (without SP).

WIN NT or 2000 server (SP3,SP4)

without (SP).

WIN 2000 Server or WIN2003 server

(SP4) without SP.

WIN2003 server or R2/WIN 2008

server with SP1.

Where SP stands for Service Pack. Service Pack are the services which are loaded

externally to remove some bugs that come during installation of server CD.

3.11.3 Requirements for Exchange Server

Protocols Required

• POP3 (Post Office Protocol)

This protocol is used for receiving e- mails.

• IMAE4 (Internet Messaging Access Protocol)

This protocol is advance version of POP, this is also used to receive mail.

• LMTP (Local Mail Transfer Protocol)/SMTP (Simple Mail Transfer Protocol)

This protocol is used to send mails.

• NNTP (Network News Transfer protocol)

This protocol is used for transferring messages on internet.

Hardware Requirements

• Processor: min. 133MHz Rec. 733MHz

• RAM: min. 256MB Rec. 512MB

Other Requirements

• OS: 2k or 2k3 Server

• NTFS partition

• Static IP address

• Active Directory

• DNS installation with AD zone

• IIS installed with ASP.net, SMTP, NNTP and www service

3.12 Open System Interconnection (OSI) Model

OSI model is the layer approach to design, develop and implement network. OSI

provides following advantages: -

(i) Development of new technology will be faster.

(ii) Devices from multiple vendors can communicate with each other.

(iii) Implementation and troubleshooting of network will be easy.

3.12.1 Description of Different Layers

Application Layer

Application layer accepts data and forward into the protocol stack. It creates user

interface between application software and protocol stack.

Presentation Layer

This layer decides presentation format of the data. It also able to performs other

function like compression/decompression and encryption/decryption.

Session Layer

This layer initiate, maintain and terminate sessions between different applications.

Due to this layer multiple application software can be executed at the same time.

Transport Layer

Transport layer is responsible for connection oriented and connection less

communication. Transport layer also performs other functions like

(i) Error checking

(ii) Flow Control

Buffering

Windowing

Multiplexing

(iii) Sequencing

(iv) Positive Acknowledgement

(v) Response

(vi)

Network Layer

This layer performs function like logical addressing and path

determination. Each networking device has a physical address that is MAC

address. But logical addressing is easier to communicate on large size network.

Logical addressing defines network address and host address. This type of

addressing is used to simplify implementation of large network. Some

examples of logical addressing are: - IP addresses, IPX addresses etc.

Network layer has different routing protocols like RIP, EIGRP, BGP, and

ARP etc. to perform the path determination for different routing protocol.

Network layer also perform other responsibilities like defining quality of service,

fragmentation and protocol identification.

Data Link Layer

The functions of Data Link layer are divided into two sub layers

• Logical Link Control

• Media Access Control

(i) Logical Link Control defines the encapsulation that will be used by the

NIC to delivered data to destination. Some examples of Logical Link

Control are ARPA (Ethernet), 802.11 wi-fi.

(ii) Media Access Control defines methods to access the shared media and

establish the identity with the help of MAC address. Some examples of

Media Access Control are CSMA/CD, Token Passing.

Physical Layer

Physical Layer is responsible to communicate bits over the media this

layer deals with the standard defined for media and signals. This layer may also perform

modulation and demodulation as required.

3.13 ROUTERS

13.13.1 Router Architecture and its Key Component

Incomplete IOS

IOS

Startup Configuration

Fig 18 : Architecture of router

Processor

Speed: - 20 MHz to 1GHz

Architecture: - RISC

Reduce Instruction set computer

Manufacturers: - Motorola, IBM, Power PC, Texas, Orion, Intel.

Flash RAM

Flash memory is just like a hard copy of the computer. Flash RAM is the

permanent read/write memory. This memory is used to store one or more copies

of router O/S. Router O/S is also called IOS (Internetwork Operating System).The

size of Flash RAM in the router is 4MB to 256MB. This memory is Electrically

Erasable Programmable Read Only Memory (EEPROM).

NVRAM

NVRAM is a “Non Volatile Random Access Memory”. It is used to store

the startup configuration of the Router. It is on chip RAM, its size is 32kb.

Processor

Memory Controller

BIOS ROM

NVRAM

RAM

Flash RAM O/S

I/O Controller

LAN

WAN

Ports

RAM (Random Access Memory)

It is a volatile memory. All the activities we do are stored in RAM,this means that

it holds the running configuration. RAM of the router is divided into two logical

parts.

• Primary RAM

• Shared RAM

Primary RAM

Primary RAM is used for: -

(i) Running copy of IOS.

(ii) Running configuration

(iii) Routing table

(iv) Address Resolution Protocol (ARP) table (IP address to MAC

address)

(v) Processor & other data structure

Shared RAM

Shared RAM is used as a buffer memory to shared the data received from

different interfaces. Size of RAM in a router may vary from 2 MB to 512 MB.

The types of memory that may be present in a RAM are:

(i) DRAM -> Dynamic RAM

(ii) EDORAM -> Extended Data Out RAM

(iii) SDRAM -> Synchronous Dynamic RAM

ROM (Random Access Memory)

It has four components:

• POST (Power on Self Test)

It performs hardware testing.

• BOOT Strap

Boot strap specifies from where and which inter operating system is to be

loaded.

• Mini IOS

Cisco 2500, 1600

• ROM MOW

333333 Router Interfaces & Ports

Interface is used to connect LAN networks or wan networks to the router.

Interface will use protocol stacks to send/receive data. Ports are used for the

configuration of routers. Ports are not used to connect different networks. The primary

purpose of port is the management of router.

33333333 Router Interface

Table 11: Router interfaces and connectors

AUI – Attachment Unit Interface

EPABX – Electronic Private Automatic Branch

PSTN – Public Services Telephone Network

3.13.2.2 Router Ports

Table 12: Router Ports

333333 Modes of Router

When we access router command prompt the router will display different modes.

According to the modes, privileges and rights are assigned to the user.

User mode

Router>

In this mode, we can display basic parameter and status of the router we can test

connectivity and perform telnet to other devices. In this mode we are not able to change

and save router configuration.

Privileged mode

Router#

In this mode, we can display all information, configuration, perform administration task,

debugging, testing and connectivity with other devices. We are not able to perform here

configuration editing of the router.

The command to enter in this mode is ‘enable’. We have to enter enable

password or enable secret password to enter in this mode. Enable secret has more priority

than enable password. If both passwords are configured then only enable secret will

work.

Global configuration

Route(config)#

This mode is used for the configuration of global parameters in the router. Global

parameters applied to the entire router. All the changes are performed in this mode. But

here we cannot see and save the changes.

For e.g: - router hostname or access list of router, password, Banner, Routing, Security.

The command to enter in this mode is ‘configure terminal’

Line configuration mode

In this mode we can set the password of the user mode, i.e to set user mode

password .This mode is used to configure lines like console, vty and auxiliary. There are

main types of line that are configured.

(i) Console

Router(config)#line console 0

(ii) Auxiliary

Router(config)#line aux 0

(iii) Telnet or vty

Router(config)#line vty 0 4

Interface configuration mode

In this mode we can set ip addresses of the interfaces. This mode is used to

configure router interfaces. For e.g:- Ethernet, Serial, BRI etc.

Router(config)#interface <type> <number>

Router(config)#interface serial 1

Routing configuration mode

This mode is used to configure routing protocol like RIP, EIGRP, OSPF etc.

Router(config)#router <protocol> [<option>]

Router(config)#router rip

Router(config)#router eigrp 10

333333 Configuring Password

There are five types of password available in a router

Console Password

router#configure terminal

router(config)#line console 0

router(config-line)#password <word>

router(config-line)#login

router(config-line)#exit

To erase password do all steps with no command.

Vty Password

router>enable

router#configure terminal

router(config)#line vty 0 4

router(config-line)#password <word>

router(config-line)#login

router(config-line)#exit

Auxiliary Password

router#configure terminal

router(config)#line Aux 0

router(config-line)#password <word>

router(config-line)#login

router(config-line)#exit

Enable Password

router>enable

router#configure terminal

router(config)#enable password <word>

router(config)#exit

Enable Secret Password

Enable Password is the clear text password. It is stored as clear text in

configuration where as enable secret password is the encrypted password.

Router>enable

Router#configure terminal

Router(config)#enable secret <word>

Router(config)#exit

Encryption all passwords

All passwords other than enable secret password are clear text password. The

command to encrypt all password are

Router#configure terminal

Router(config)#service password-encryption

3.13.5 Managing Configuration

There are two types of configuration present in a router

(i) Startup Configuration

(ii) Running Configuration

Startup configuration is stored in the NVRAM. Startup configuration is used to

save settings in a router. Startup configuration is loaded at the time of booting in to the

Primary RAM.

Running Configuration is present in the Primary RAM wherever we run a

command for configuration, this command is written in the running configuration.

To save configuration

Router#copy running-configuration startup-configuration

Or

Router#write

To abort configuration

Router#copy startup-configuration running-configuration

To display running-configuration

Router#show running-configuration

To display startup configuration

Router#show startup-configuration

Configuring Host Name

Router#configure terminal

Router(config)#hostname <name>

<name>#exit or end or /\z

Router#config terminal

Router(config)#hostname r1

R1(config)#

Configuration Interfaces

Interfaces configuration is one of the most important part of the router

configuration. By default, all interfaces of Cisco router are in disabled mode. We have to

use different commands as our requirement to enable and configure the interface.

Router#configure terminal

Router(config)#interface <type> <no>

Router(config-if)#ip address <ip> <mask>

Router(config-if)#no shutdown

Router(config-if)#exit

To display interface status

Router#show interfaces (to show all interfaces)

Router#show interface <type> <no>

This command will display following parameters about an interface

(1) Status

(2) Mac address

(3) IP address

(4) Subnet mask

(5) Hardware type / manufacturer

(6) Bandwidth

(7) Reliability

(8) Delay

(9) Load ( Tx load Rx load)

(10) Encapsulation

(11) ARP type (if applicable)

(12) Keep alive

Configuring optional parameter on WAN interface

Router#configure terminal

Router(config)#interfac <type> <no>

Router(config-if)#encapsulation <protocol>

Router(config-if)#clock rate <value>

Router(config-if)#end

Command displaying history of Router

• To display commands present in history

Router#show history

• To display history size

Router#show terminal

• To change history size

Router#config terminal

Router(config)#line console 0

Router(config-if)#history size <value(0-256)>

Router(config-if)#exit

Configuring Banners

Banners are just a message that can appear at different prompts according to the type.

Different banners are: -

• Message of the day (motd)

This banner appear at every access method

• Login

Appear before login prompt

• Exec

Appear after we enter to the execution mode

• Incoming

Appear for incoming connections

Syntax:-

Router#config terminal

Router(config)#banner <type> <delimation char>Text Massage

<delimation char>

Router(config)#

Example

Router#config terminal

Router(config)#banner motd $ This router is distribution 3600 router

connected to Reliance $

Router(config)#

To set time in router

We can configure router clock with the help of two methods:

(i) Configure clock locally

(ii) Configure clock on NTP server (Network Time Protocol)

Router does not have battery to save the clock setting. So that clock will reset to the

default on reboot.

To display clock

Router#show clock

To configure clock

Router#clock set hh:mm:ss day month year

Router#clock set 7:15:10 9 June 2009

To configure clock from NTP server

Router#config terminal

Router(config)#ntp server <IP address>

Router(config)#exit

C:\>ping pool.ntp.org

To get ntp server ip from internet

C:\>route print

3.14 SUBNETTING

Subnetting is a process or a technique to divide large and complex networks into

smaller parts or smaller networks and each network is called as subnet. Subnetting is

done to reduce the wastage of IP addresses ie instead of having a single huge network for

an organization smaller networks are created within a given huge network. Subnetting

allows the user to create multiple logical networks within a single Class A, B or C based

networks.

In subnetting, the IPv4 address is broken into two parts; network id and host id.

This process borrows bits from the host id field. In this process, the network size does not

shrink but the size of hosts per network shrinks in order to include sub-networks within

the network.

333333 Advantages of subnetting

• Size of the physical networks is reduced and hence easy to manage.

• Reduce network traffic.

• Easy to troubleshoot.

• Reduce the wastage of IP address.

Subnet Mask

A subnet mask specifies the part of IP address that is to be used for identifying a

sub network. A subnet mask when logically ANDed with IPaddress provides a 32- bit

network address. This binary address gives the first address in the subnet block specified

in the large network.

Default Mask

Classfull addresses consists of three classes; Class A, Class B, Class C used for

subnet.Each class has a default subnet mask C lass A consists of eight 1s in the network

address field and 24 0s in remaining field, Class B consists of 16 1s in network address

field and 16 0s in remaining field, and Class C cointains 24 1s in the network address

field and remaining 8 bytes as 0s. the default address mask in binary and dotted-decimal

is shown in the table

To Calculate the Subnet Mask1. Identify the class of address assigned. For this example the class of IP address

is Class B.

2. check the default address mask for the appropriate class and convert it to

binary format .for this example the default address mask is 255.255.0.0 and

the equivalent binary format is; 11111111.11111111.00000000.00000000

3. check the no. of 1s in the default mask. E.g this address contains 16 1s in class

B, 16 bits 2 octat are for net id and the last 16 bits 2 octates are for host id.

4. now if we need 9 subnets. This no. 9 is not a power of 2. the next no. that is

power of 2 and greater than 2 is 16. So, we require 4 extra 4 extra 1s in the

network field which has to be borrowed from the host id field.

5. the total no. of 1s is 16+4=20, as 16 1s are from network id and 4 1s are of

additional bits required for subnetwork. The no. of 0s in the n/w is 32-20=12.

which defines whole address.

6. hence address is given as 11111111.11111111.11110000.00000000 and in

decimal format can be given as 255.255.240.0

Table 14: decimal and binary values of subnet mask

DecimalBinary

0

128

192

224

240

248

252

254

255

00000000

10000000

11000000

11100000

11110000

11111000

11111100

11111110

11111111

333333 Types of Subnetting

• Fixed Length Subnet Mask (FLSM)

• Variable Length Subnet Mask (VLSM)

Steps of Subnetting for FLSM

For IP address 192.168.10.0 (Class C)

Step 1:

• Identify the total no. of subnets 2^n = no.of subnets

• Where n are the no.s and borrowed bytes from host ID portion. Let we are given

that we have to make 4 subnets. Therefore 2^n =4 i.e n=2

Step 2:

• To idettify the total no. of the valid hosts for each subnet.

• 2^m-2= no.of valid hosts. Where m are the remaining no. of bits in host ID 2^6-

2=62

Step 3:

• Calculate the subnet mask and range

• Subnet mask for n/w 192.168.10.0/26 is

11111111.11111111.11111111.1100000000 ie 255.255.255.192

• range=> 256-192=64

step 4:

• Identify the total no of subnets, no. of valid hosts and the broadcast address.

Table 15: showing subnet mask, valid hosts, broadcast address

Subnetwork Valid Host Broadcast Address

192.168.10.0

192.168.10.64

192.168.10.12

8

192.168.10.19

2

192.168.10.1 to

192.168.10.63

192.168.10.65 to

192.168.10.126

192.168.10.129 to

192.168.10.190

192.168.10.193 to

192.168.10.254

192.168.10.63

192.168.10.127

192.168.10.191

192.168.10.255

VLSM

In VLSM to allocate IP addresses to subnets depending upon the no. of hosts. The

network having more no of hosts is given priority and the one having least no of host

comes at last and for each network the subnet is assigned separately. As in the scenario

given:

Fig 19: variable subnet mask

3.15 TELNET

Telnet stands for terminal network, telephone network, terminal encapsulation on

the network. Purpose of Telnet is to access the remote device in order to configure it. It

provides textual access of the remote device. It uses the services of TCP. Telnet service is

used where small bandwidth is low. It provides textual access of the remote device. Port

number of Telnet is 23.

3.15.1 To Access the Device Remotely

For this purpose we have to assign the IP addresses to the PCs and the interfaces.

For Telnet the Routers are to be configured with RIP version1 , so that the device can

ping each other. Also DCE cable is used to connect the Routers. The serial link should

have the speed of 64K also apply vty password and enable secret password. Set up the

Routers so that they can manage via Telnet.

First of all select the PCs and the routers connect the ports to the router, double

click on router, switch off the router if it is on. Then select the serial port according to the

routers, switch on the router. Select the cable to connect the Routers. Router to Router

connections are made by the serial cable, so go on first Router select the serial port as

s0/1/0 in the scenario, then go to the other Router and connect the serial cable at interface

s1/0. Accordingly connect the third Router with interfaces s1/1 and s1/2.

Now connect the PCs to the routers, to do this first select the console cable, click on the

PC select RS232 option, then connect it on the Router and select console cable. Now

select cross- over cable on the PC select Fast Ethernet option and on the Router select

f0/0 option now as the PCs and Routers are connected to each other assign IP addresses

to the PCs and the Routers. According to the fig set the IP addresses of the PCs→ double

click on the PC→ choose the option of desktop→ IP configuration. Now set the IP

address, subnet mask, and the default gateway. Like wise set the IP address of all the

PCs. Now set the IP address of the interfaces of router.

3.15.2 Commands to assign IP addresses to the interfaces:

At Router1:

Router>

Router>enable

Router#configure terminal

Router(config)#interface f0/0

Router(config-if)#ip address 10.0.0.1 255.0.0.0

Router(config-if)#no shutdown

Fig 20: scenario of Telnet

Router#

Router#configure terminal

Router(config)#interface s0/1/0

Router(config-if)#ip address 40.0.0.1 255.0.0.0

Router(config-if)#no shutdown

Router(config)#interface s0/1/0

Router(config-if)#clock rate 64000

Router(config-if)#no shutdown

Now to check the assigned IPaddresses to the interfaces the command used is

Router#show ip interface brief

At router 2:

Router#configure terminal

Router(config)#interface f0/0

Router(config-if)#ip address 20.0.0.1 255.0.0.0

Router(config-if)#no shutdown

Router#

Router#configure terminal

Router(config)#interface s1/0

Router(config-if)#ip address 40.0.0.2 255.0.0.0

Router(config-if)#no shutdown

Router#configure terminal

Router(config)#interface s1/1

Router(config-if)#ip address 50.0.0.1 255.0.0.0

Router(config-if)#no shutdown

Router(config)#interface s1/1

Router(config-if)#clock rate 64000

Router(config-if)#no shutdown

At router 3:

Router#configure terminal

Router(config)#interface f0/0

Router(config-if)#ip address 30.0.0.1 255.0.0.0

Router(config-if)#no shutdown

Router#

Router#configure terminal

Router(config)#interface s1/0

Router(config-if)#ip address 50.0.0.2 255.0.0.0

Router(config-if)#no shutdown

To Telnet a device from Router

At all the Routers use these commands

Router(config)#line vty 0 4

Router(config-line)#password cobra

Router(config-line)#login

Router(config)#enable password cobra

Router(config)#enable secret cobra1

To telnet a device from router

Router#telnet <IP>

Or

Router>telnet <IP>

To exit from telnet session

Router#exit

To exit from a hanged telnet session

Ctrl+shft+6

Or

Router#disconnect

To display connected session

Router#show sessions

This command shows those sessions, which are created or connected by us.

If we want anyone can telnet our router without password then on the line vty type

command “No Login”.

3.16 ROUTING

Routing is a process or technique to identify the path from one network to

another. Routers don’t really care about hosts—they only care about networks and the

best path to each network.

To route the packet the router must know the following things:

• Destination network

• Neighbour device from witch it can learn about remote Networking.

• Possible number of routers to reach the destination.

• Best route to reach the destination.

• How to maintain & verify the routing information.

3.16.1 TYPES OF ROUTING

• Static routing.

• Default routing.

• Dynamic routing.

3.16.1.1 STATIC ROUTING

In static routing an administrator specifies all the routes to reach the destination.

Static routing occurs when you manually add routes in each router’s routing table.By default,

Static routes have an Administrative Distance (AD) of 1

Features

There is no overhead on the router CPU.

There is no bandwidth usage between routers.

It adds security, because the administrator can choose to allow routing access to certain

networks only.

Advantages of static routing

(1) Fast and efficient.

(2) More control over selected path.

(3) Less overhead for router.

(4) Bandwidth of interfaces is not consumed in routing updates.

Disadvantages of static routing

(1) More overheads on administrator.

(2) Load balancing is not easily possible.

(3) In case of topology change routing table has to be change manually.

Syntax for Static Routing

Router (config)# ip route <destination N/w> <Subnet mask> <Next

Hope- address or exit interface> [<administrative distance>Permanent].

To check the routing table of router

Router # show ip route

Fig 21: scenario of static routing

Static routing of router (R1)

Router(config)#ip route 20.0.0.0 255.0.0.0 40.0.0.2

Router(config)#ip route 30.0.0.0 255.0.0.0 40.0.0.2

Router(config)#ip route 50.0.0.0 255.0.0.0 40.0.0.2

Router(config)#interface so/1/0

Router(config)# clock rate 64000

Router # show ip route

Static routing of router (R2)

Router(config)#ip route 10.0.0.0 255.0.0.0 40.0.0.1

Router(config)#ip route 30.0.0.0 255.0.0.0 50.0.0.2

Router#show ip route

Router(config)#interface s1/0

Router(config)# clock rate 64000

Router(config)#interface s1/1

Router(config)#clock rate 64000

Router#show ip route

Static routing of router (R3)

Router(config)#ip route 10.0.0.0 255.0.0.0 50.0.0.1

Router(config)#ip route 20.0.0.0 255.0.0.0 50.0.0.1

Router(config)#ip route 40.0.0.0 255.0.0.0 50.0.0.1

Router(config)#interface s1/0

Router(config)# clock rate 64000

Router#show ip route

3.16.1.2 DEFAULT ROUTING

Default routing is used to send packets with a remote destination network

not in the routing table to the next-hop route.

Default routing is also a type of static routing which reduces the routing

overhead & default routing is also used with stub networks. Stub networks are those

having a single exit interface. Default routing is also used for unknown destination.

A special address is used to perform the default routing ie 0.0.0.0

The scenario for default routing is same and but the commands used at the routers

having single exit interface like R1 and R3 have different commands.

At Router (R1)

Router(config)#ip route 0.0.0.0 0.0.0.0 40.0.0.2

Router#show ip route

At Router (R3)

Router(config)#ip route 0.0.0.0 0.0.0.0 50.0.0.1

Router#show ip route

3.16.1.3 DYNAMIC ROUTING

Dynamic routing is when protocols are used to find networks and update

routing table on routers.

A routing protocol defines the set of rules used by router when it communicates

routing information between neighbor routers. In dynamic routing, we will enable a

routing protocol on router. This protocol will send its routing information to the neighbor

router. The neighbors will analyze the information and write new routes to the routing

table.

The routers will pass routing information receive from one router to other

router also. If there are more than one path available then routes are compared and best

path is selected. Some examples of dynamic protocol are: -

RIP, IGRP, EIGRP, OSPF

There are two type of routing protocols used in internetwors:

• Interior Gateway Protocols (IGPs)

IGPs are used to exchange routing information with routers in the same

Autonomous System(AS) number. Routing which is performed within a single

autonomous system is known as interior routing. The protocol that are used to perform

this type of routing are known as IGP(Interior Gateway Protocol).

These protocols are:-

(i) RIPv1 (Routing Information Protocol Version 1)

(ii) RIPv2 (Routing Information Protocol Version 2)

(iii) EIGRP (Enhanced Interior Gateway Routing Protocol)

(iv) OSPF (Open Shortest Path First)

(v) IS-IS (Intermediate System to Intermediate System)

• Exterior Gateway Protocols (EGPs)

EGPs are used to communicate between different Autonomous System.

Protocol that used to do this type of routing are called exterior gateway protocols.

Autonomous System:- An autonomous system is a collection of networks under a

common administrative domain, which basically means that all routers sharing the same

routing table information are in the same AS.

3.16.2 Routing Protocol Basics

(i) Administrative Distances

(ii) Routing protocol

(iii) Routing Loops

• Administrative Distances

The Administrative Distance (AD) is used to rate the trustworthiness of routing

information received on a router from a neighbor router. An Administrative Distance is

an integer from 0 to 255, where 0 is the most trusted and 255 means no traffic will be

passed via this route.

If a router receives two updates listing he sane remote network, the first thing the router

checks is the AD. If one of the advertised routes has lower AD than the other, then the

route with the lowest AD will be placed in the routing table.If both advertised routes to

the same network have the same AD, then routing protocol metrics (such as hop count or

bandwidth of the lines) will be used to find the best path to the remote network. The

advertised route with the lowest metric will be placed in the routing table.

But if both advertised routes have the same AD as well as the same metrics, then the

routing protocol will load-balance in the remote network.

3.16.2.1 Classes of Routing Protocols

There are three classes of Routing Protocol

(i) Distance vector protocol

(ii) Link state protocol

(iii) Hybrid protocol.

• Distance vector protocol

The Distance-vector protocols find the best path to remote network by

judging distance. Each time a packet goes through a router, that’s called a hop. The route

with the least number of hops to the network is determined to be the best route. The

vector indicates the direction to the remote network. They send the entire routing table to

directly connected neighbors.

Ex: RIP, IGRP.

The distance-vector routing algorithm passes complete routing table contents to

neighboring routers.

A router receiving an update from a neighbor router believes the information

about remote networks without actually finding out for itself.

It’s possible to have network that has multiple links to the same remote network,

and if that’s the case, the administrative distance is checked first. If the AD is the

Route Source Default AD

Connected interface 0

Static Route 1

EIGRP 90

IGRP 100

OSPF 110

RIP 120

External EIGRP 170

Unknown 255 This route will never be used

same, the protocol will have to use other metrics to determine the best path to use

to that remote network.

Fig 16: Routing table

Converged Network

Fig 23 : Routing table of covered networks

• Routing Loops

Distance-vector routing protocols keep track of any changes to the internet work

by broadcasting periodic routing updates out all active interfaces. This broadcast includes

the complete routing table.

Routing loops can occur because a every router isn’t updated simultaneously.

Routing Loops Example

Router A Router B

Router D

Router C Router E

Network 3 Network 4 Network 5

Fig 24: Routing loops

The interface to Network 5 fails. All routers know about Network 5 from Router

E. Router A, in its tables, has a path to Network 5 through Router B.

When Network 5 fails, Router E tells Router C. This causes Router C to stop

routing to Network 5 through Router E. But Routers A, B, and D don’t know about

Network 5 yet, so they keep sending out update information. Router C will eventually

send out its update and cause B to stop routing to Network 5, but Routers A and D are

still not updated. To them, it appears that Network 5 is still available through Router B

with a metric of 3.The problem occurs when Router A sends out its regular 30-second

“Hello, I’m still here—these are the links I know about” message, which includes the

ability to reach Network 5 and now Routers B and D receive the wonderful news that

Network 5 can be reached from Router A, so Routers B and D then send out the

information that Network 5 is available. Any packet destined for Network 5 will go to

Router A, to Router B, and then back to Router A. This is a routing loop.

• Link state protocol

Also called shortest-path-first protocols, the routers each create three

separate tables. One keeps track of directly attached neighbors, one determines the

topology of the entire internet work, and one is used as the routing tables. Link state

routers know more about the internet work than any distance-vector routing protocol.

Link state protocols send updates containing the state of their own links to all other

routers on the network

Ex: OSPF

• Hybrid protocol

Hybrid protocol use aspects of both distance-vector and link state protocol.

Ex: EIGRP

3.16.3 RIP (Routing Information Protocol)

Routing Information Protocol is a true distance-vector routing protocol. It

is an IGB (Inter Gateway Protocol). It sends the complete routing table out to all active

interfaces every 30 seconds to its immediate neighbour. This is slow convergence means

that one router sends a request to other about its route or network get networks which are

not assigned to it after all thee three routers have same networks, this process is repeated

to send and receive request so it is called slow convergence

RIP only uses hop count to determine the best way to remote network, but

it has a maximum allowable hop count of 0-15 by default, meaning that 16 is deemed

unreachable.

RIP version 1 uses only class full routing, which means that all devices in

the network must use the same subnet mask.

RIP version 2 provides something called prefix routing, and does send

subnet mask information with the route updates. This is called classless routing.

• Hop Count

It is a way of measurement. Hop count limit is15.This routing supports only 15

routers, if there is one more router in the network then this routing will fails.

• Default administrative distance (120)

Timers of RIP

(i) Update timers.

(ii) Hold timers.

(iii) Invalid timers.

(iv) Flush out timers.

Route update timer

Router update timer sets the interval 30 seconds between periodic routing

updates, in which the router sends a complete copy of its routing table out to all

neighbors.

Router invalid timers

A router invalid timer determines the length of time that must elapse 180 seconds

before a router determines that a route has become invalid. It will come to this conclusion

if it hasn’t heard any updates about a particular route for that period. When that happens,

thee router will send out updates to all its neighbors letting them know that the route is

invalid.

Hold-down timer

This sets the amount of time during which routing information is suppressed.

Routers will enter into the hold-down state when an update packet is received that

indicated the route is unreachable. This continues until entire an update packet is received

with a better metric or until the hold-down timer expires. The default is 180 seconds.

Route flush timer

Route flush timers’ sets the time between a route becoming invalid and its interval

from the routing table 240 seconds. Before it’s removed from the table, the router notifies

its neighbors of that route’s impending demise. The value of the route invalid timer must

be less than that of the route flush timers.

Difference between RIPV1 & RIPV2

Steps to do routing (version 1)

At router 1

Router(config)# router rip

Router(config-router)#network 10.0.0.0

Router(config-router)#network 40.0.0.0

Router#show ip route

At router 2

Router(config)# router rip

Router(config-router)#network 20.0.0.0

Router(config-router)# network 40.0.0.0

Router(config-router)# network 50.0.0.0

Router#show ip route

At router 3

Router(config)# router rip

Router(config-router)#network 30.0.0.0

Router(config-router)# network 50.0.0.0

Router#show ip route

3.16.4 IGRP ( Interior Gateway Protocol)

Interior Gateway Routing Protocol (IGRP) is a Cisco-proprietary distance-vector

routing protocol. To use IGRP, all your routers must be Cisco routers. IGRP has a

maximum hop count of 255 with a default of 100. IGRP uses bandwidth and delay of the

line by default as a metric for determining the best route to an internetwork. Reliability,

load, and maximum transmission unit (MTU) can also be used, although they are not

used by default.

Table 18 : Difference between IGRP and RIP

IGRP RIP

Can be used in large internetworks Works best in smaller networks

Uses an autonomous system number for

activation

Does not yse aytibiniys system numbers

Gives a full route table update every 90

seconds

Gives full route table update every 30

seconds

Has an administrative distance of 100 Has an administrative distance of 120

Uses bandwidth and delay of the line as

metric (lowest composite metric),with a

maximum hop count of 255

Uses only hop count to determine the best

path to a remote network, with 15 hops

being the maximum

IGRP Timers

To control performance, IGRP includes the following timers with default settings:

• Update timers

These specify how frequently routing-update messages should be sent. The

default is 90 seconds.

• Invalid timers

These specify how long a router should wait before declaring a route invalid if it

doesn’t receive a specific update about it. The default is three times the update period.

• Hold down timers

These specify the hold down period. The default is three times the update timer

period plus 10 seconds.

• Flush timers

These indicate how much time should pass before a route should be flushed from

the routing table. The default is seven times the routing update period. If the update timer

is 90 seconds by default, then 7 × 90 = 630 seconds elapse before a route will be flushed

from the route table.

At Router 1

R1(config)#router igrp 10

R1(config-router)#network 10.0.0.0

R1(config-router)#network 40.0.0.0

R1#show ip route

At Router 2

R2(config)#router igrp 10

R2(config-router)#network 40.0.0.0

R2(config-router)#network 20.0.0.0

R2(config-router)#network 50.0.0.0

R2#show ip route

At Router 3

R1(config)#router igrp 10

R1(config-router)#network 30.0.0.0

R1(config-router)#network 50.0.0.0

R1#show ip route

3.16.5 EIGRP(Enhanced Interior Routing Protocol)

Enhanced IGRP (EIGRP) is a classless, enhanced distance-vector protocol

that gives us a real edge over IGRP. Like IGRP, EIGRP uses the concept of an

autonomous system to describe the set of contiguous routers that run the same routing

protocol and share routing information. But unlike IGRP, EIGRP includes the subnet

mask in its route updates. The advertisement of subnet information allows us to use

VLSM and summarization when designing our networks.

EIGRP is sometimes referred to as a hybrid routing protocol because it has

characteristics of both distance-vector and link-state protocols. It sends traditional

distance-vector updates containing information about networks plus the cost of

reaching them from the perspective of the adverting router. EIGRP has a maximum

hop count of 255.

Powerful features that make EIGRP a real standout from IGRP

• Support for IP, IPX, and AppleTalk via protocol-dependent modules Considered

classless (same as RIPv2 and OSP

• Support for VLSM/CIDR

• Support for summaries and discontiguous networks

• Efficient neighbor discovery

• Communication via Reliable Transport Protocol (RTP)

• Best path selection via Diffusing Update Algorithm (DUAL)

Cisco calls EIGRP a distance vector routing protocol, or sometimes an

advanced distance vector or even a hybrid routing protocol. EIGRP supports different

Network layer protocols through the use of protocol-dependent modules (PDMs). Each

EIGRP PDM will maintain a separate series of tables containing the routing information

that applies to a specific protocol. It means that there will be IP/EIGRP tables,

IPX/EIGRP tables, and AppleTalk/EIGRP tables.

Neighbor Discovery

Before EIGRP routers are willing to exchange routes with each other, they must

become neighbors. There are three conditions that must be met for neighborship

establishment:

Hello or ACK received

AS numbers match

Identical metrics (K values)

To maintain the neighborship relationship, EIGRP routers must also continue

receiving Hellos from their neighbors. EIGRP routers that belong to different

autonomous systems (ASes) don’t automatically share routing information and they don’t

become neighbors.

The only time EIGRP advertises its entire routing table is when it discovers a new

neighbor and forms an adjacency with it through the exchange of Hello packets. When

this happens, both neighbors advertise their entire routing tables to one another. After

each has learned its neighbor’s routes, only changes to the routing table are propagated

from then on.

EIGRP maintains three tables containing information about the internetworks.

(i) Neighbor Table

Records information about routers with whom neighborship relationships

have been formed.

(ii) Topology Table

Stores the route advertisements about every route in the internetwork received

from each neighbor.

EIGRP Metrics

Another really sweet thing about EIGRP is that unlike many other protocols that

use a single factor to compare routes and select the best possible path, EIGRP can use a

combination of four:

• Bandwidth

• Delay

• Load

• Reliability

3.16.6 OSPF (Open Shortest Path First)

Open Shortest Path First (OSPF) is an open standards routing protocol that’s been

implemented by a wide variety of network vendors, including Cisco. This works by using

the Dijkstra algorithm. First, a shortest path tree is constructed, and then the routing table

is populated with the resulting best paths. OSPF converges quickly, although perhaps not

as quickly as EIGRP, and it supports multiple, equal-cost routes to the same destination.

But unlike EIGRP, it only supports IP routing.

OSPF is an IGP protocol. It is a link state routing protocol. It is supported by

many operating systems. Its default AD is 110, hop count limit is unlimited.

It is classless routing protocol, supports VLSM/CIDR. By default the highest IP address

of interface will be elected as Router id.

OSPF provides the following features

Consists of areas and autonomous systems

Minimizes routing update traffic

Allows scalability

Supports VLSM/CIDR

Has unlimited hop count

Allows multi-vendor deployment (open standard)

OSPF is supposed to be designed in a hierarchical fashion, which basically means

that you can separate the larger internetwork into smaller internetworks called areas. This

is the best design for OSPF.

The reasons for creating OSPF in a hierarchical design include:

• To decrease routing overhead

• To speed up convergence

• To confine network instability to single areas of the network

Each router in the network connects to the backbone called area 0, or the

backbone area. OSPF must have an area 0, and all routers should connect to this area if

at all possible. But routers that connect other areas to the backbone within an AS are

called Area Border Routers (ABRs). Still, at least one interface must be in area 0.

OSPF runs inside an autonomous system, but can also connect multiple

autonomous systems together. The router that connects these ASes together is called an

Autonomous System Boundary Router (ASBR).

OSPF Terminology

• Link

A link is a network or router interface assigned to any given network. When an

interface is added to the OSPF process, it’s considered by OSPF to be a link.

• Router ID

The Router ID (RID) is an IP address used to identify the router. Cisco chooses

the Router ID by using the highest IP address of all configured loopback interfaces. If no

loopback interfaces are configured with addresses, OSPF will choose the highest IP

address of all active physical interfaces.

• Neighbors

Neighbors are two or more routers that have an interface on a common

network,such as two routers connected on a point-to-point serial link.

• Adjacency

An adjacency is a relationship between two OSPF routers that permits the direct

exchange of route updates. OSPF is really picky about sharing routing information—

unlike EIGRP, which directly shares routes with all of its neighbors. Instead, OSPF

directly shares routes only with neighbors that have also established adjacencies. And not

all neighbors will become adjacent—this depends upon both the type of network and the

configuration of the routers.

OSPF Topologies database

The topology database contains information from all of the Link State

Advertisement packets that have been received for an area. The router uses the

information from the topology database as input into the Dijkstra algorithm that computes

the shortest path to every network. LSA packets are used to update and maintain the

topology database.

A Link State Advertisement (LSA) is an OSPF data packet containing link-state

and routing information that’s shared among OSPF routers. There are different types of

LSA packets. An OSPF router will exchange LSA packets only with routers to which it

has established adjacencies.

A designated router (DR) is elected whenever OSPF routers are connected to the

same multi-access network. A prime example is an Ethernet LAN.

A backup designated router (BDR) is a hot standby for the DR on multi-access

links The BDR receives all routing updates from OSPF adjacent routers, but doesn’t

flood LSA updates.

OSPF areas

An OSPF area is a grouping of contiguous networks and routers. All routers in the

same area share a common Area ID.

Broadcast (multi-access)

Broadcast (multi-access) networks such as Ethernet allow multiple devices to

connect to (or access) the same network, as well as provide a broadcast ability in which a

single packet is delivered to all nodes on the network. In OSPF, a DR and a BDR must be

elected for each broadcast multi-access network.

Non-broadcast multi-access

Non-Broadcast Multi-Access (NBMA) networks are types such as Frame Relay,

X.25, and Asynchronous Transfer Mode (ATM). These networks allow for multi-access,

but have no broadcast ability like Ethernet. So, NBMA networks require special OSPF

configuration to function properly and neighbor relationships must be defined.

• Point-to-point

Point-to-point refers to a type of network topology consisting of a direct

connection between two routers that provides a single communication path. The point-to-

point connection can be physical, as in a serial cable directly connecting two routers, or it

can be logical.

• Point-to-multipoint

Point-to-multipoint refers to a type of network topology consisting of a series of

connections between a single interface on one router and multiple destination routers. All

of the interfaces on all of the routers sharing the point-to-multipoint connection belong to

the same network. As with point-to-point, no DRs or BDRs are needed.

SPF Tree Calculation

Within an area, each router calculates the best/shortest path to every network in

that same area. This calculation is based upon the information collected in the topology

database and an algorithm called shortest path first (SPF)

OSPF uses a metric referred to as cost. A cost is associated with every outgoing

interface included in an SPF tree. The cost of the entire path is the sum of costs of the

outgoing interfaces along the path.

Cisco uses a simple equation of 108/ bandwidth.The bandwidth is the configured

bandwidth for the interface. Using this rule, a 100Mbps Fast Ethernet interface would

have a default OSPF cost of 1 and a 10Mbps Ethernet interface would have a cost of 10.

An interface set with a bandwidth of 64,000 would have a default cost of 1563.

Benefits of OSPF

(i) Minimum routing updates.

(ii) Priorities on all the CISCO routers the priority is 1.

(iii) The routers having highest IP address become BRD(Border Destination

Router)

Steps to apply OSPF

Syntax:

Router(config)#router ospf <ospf process id>

Router(config-router)#network <network address> <wild card mask> area

<area number>

Fig 25: OSPF Scenario

At Router r1

Router(config)#router ospf 1

Router(config-router)#network 10.0.0.0 0.255.255.255 area 0

Router(config-router)#network 10.0.0.0 0.255.255.255 area 0

Router(config)#interface s0/1/0

Router(config-if)#clock rate 64000

Router#show ip route

At Router r1

Router(config)#router ospf 2

Router(config-router)#network 20.0.0.0 0.255.255.255 area 0

Router(config-router)#network 40.0.0.0 0.255.255.255 area 0

Router(config-router)#network 50.0.0.0 0.255.255.255 area 0

Router(config)#interface s0/1/0

Router(config-if)#clock rate 64000

Router#show ip route

At Router r3

Router(config)#router ospf 1

Router(config-router)#network 30.0.0.0 0.255.255.255 area 0

Router(config-router)#network 50.0.0.0 0.255.255.255 area 0

Router#show ip route

3.17 LAN SWITCHING

3.17.1 SWITCH

Switches are generally used to segment a large LAN smaller segments. Smaller

switches such as the Cisco Catalyst 2924XL have 24 ports capable of of creating 24

different network segment for the LAN. Larger switches such as the Cisco Catalyst 6500

can have hundreds of ports. Switches can also be used to connect LANs with different

media, for example, a 10 Mbps Ethernet LAN and 100 Mbps Ethernet LAN can be

connected using a switch. Some switches support cut through switching, witch reduces

latency and delays in the network, while bridges support only store-and-forward traffic

switching. Finally switches reduce collision on network segment . A switch is a

networking device which filters and forward packets through the network. It is a layer 2

device. It is more advanced then hub but not as advanced as router.The basic function of

a switch is to manage the signal flow. When the switch is open, it allows the signal to

flow through it and when it is closed, it stopes the signal to flow. Switch connects

separate LAN segment. It allows multiple system to transmit simultaneously. A switch is

a hardware device that filters and forward data packets between network segments.

Ethernet switches are used in LAN to create Ethernet networks. Switches forward the

traffic on the basis of MAC address. Switches maintain a switching table in which MAC

addresses and port numbers are used to perform switching decision.

WORKING OF SWITCH

When switches receives data from one of connected devices, it forward data only

to the port on witch the destinated system is connected.It use the media access Control

(MAC) address of the device to determine the correct port.The MAC address is a uniqe

number that is programed in to every Network Interface Card(NIC). Concider, device A

wants to send data to device B.When device A passes the data, switch receives it. Switch

than cecks the MAC address of the destination system. It then transfer data to device B

only instead of brodcasting to all the devices. By forwarding data only to the system to

witch the data is addressed, switch decreases the amount of traffic on each network link.

SWITCHING METHODS

There are three types of switching method:

• Store-and-forward switching

The entire frame is received and the CRC is computed and verified before

forwarding the frame. If the frame is too short (i.e. less than 64 bytes including the

CRC), too long (i.e. more than 1518 bytes including the CRC), or has CRC error, it

will be discarded.

It has the lowest error rate but the longest latency for switching. However, for

high-speed network (e.g. Fast Ethernet or Gigabit Ethernet network), the latency is

not significant. It is the most commonly used switching method, and is supported by

most switches.

• Cut-through switching

It is also known as Fast Forward switching. A frame is forwarded as soon as

the destination MAC address in the header has been received (the 1st 6 bytes

following the preamble). It has the highest error rate (because a frame is

forwarded without verifying the CRC and confirming there is no collision) but

the shortest latency for switching

• Fragment-free switching ( Modified Cut-through switching )

A frame is forwarded after the first 64 bytes of the frame have been

received. Since a collision can be detected within the first 64 bytes of a frame,

fragment-free switching can detect a frame corrupted by a collision and drop

it.Therefore, fragment-free switching provides better error checking than cut-

through switching.

The error rate of fragment-free switching is above store-and-forward

switching and below cut-through switching. The latency of fragment-free

switching is shorter than store-and- forward switching and longer than cut-

through switching.

NOTE: Bridges only support store-and-forward switching. Most new switch models also

use store-and-forward switching. However, it should be noted that Cisco 1900 switches

use fragment-free switching by default.

Types of switch based on OSI model

(i) Layer-2 switch

(ii) Layer-3 switch

• Layer-2 Switching

Layer-2 switching is hardware based, which means it uses the MAC

address from the host NIC card to filter the network traffic. Layer-2 switch can be

considered as multi- port bridge.

Layer 2 switches are fast because they do not look at the network layer

header information, instead it looks at the frames hardware address before deciding to

either forward the frame or drop it.

Limitations of Layer 2 Switching

With bridge the connected networks are still one large broadcast domain.

Layer 2 switch cannot break the broadcast domain, this cause performance issue which

limits the size of your network. For this one reason the switch cannot completely replace

routers in the internetwork.

3.17.1.1 VLAN (Virtual LAN)

VLAN provides Virtual Segmentation of Broadcast Domain in the network. The

devices, which are member of same Vlan, are able to communicate with each other. The

devices of different Vlan may communicate with each other with routing. So that

different Vlan devices will use different n/w addresses.

Vlan provides following advantages: -

• Logical Segmentation of network

• Enhance network security

Creating port based Vlan

In port based Vlan, first we have to create a Vlan on manageable switch then we

have to add ports to the Vlan. A Virtual LAN (VLAN) is a broadcast domain created

based on the functional, security, or other requirements, instead of the physical locations

of the devices, on a switch or across switches. With VLANs, a switch can group different

interfaces into different broadcast domains. Without VLANs, all interfaces of a switch

are in the same broadcast domain; switches connected with each other are also in the

same broadcast domain, unless there is a router in between. Different ports of a switch

can be assigned to different VLANs. A VLAN can also span multiple switches.

The advantages of implementing VLAN are

• It can group devices based on the requirements other than their physical

locations.

• It breaks broadcast domains and increases network throughput.

• It provides better security by separating devices into different VLANs.

• Since each VLAN is a separate broadcast domain, devices in different VLANs

cannot listen or respond to the broadcast traffic of each other.

• Inter-VLAN communication can be controlled by configuring access control

lists on the router or Layer 3 switch connecting the VLANs.

Types of VLAN

• Static VLAN

Assigning VLANs to switch ports based on the port numbers. It is easier to set

up and manage.

• Dynamic VLAN

Assigning VLANs to switch ports based on the MAC addresses of the

devices connected to the ports.

A VLAN management application is used to set up a database of MAC addresses, and

configure the switches to assign VLANs to the switch ports dynamically based on the

MAC addresses of the connected devices. The application used by Cisco switches is

called VLAN Management Policy Server (VMPS).

Cisco switches support a separate instance of spanning tree and a separate bridge

table for each VLAN.

A VLAN = A Broadcast Domain = Logical Network (Subnet)

VLAN Operation

Fig 26: VLAN Operation

• Each logical VLAN is like a separate physical bridge.

• VLANs can span across multiple switches.

• Trunks carry traffic for multiple VLANs.

• Trunks use special encapsulation to distinguish between different VLANs.

VLAN links

There are two different types of links in a switched network:

• Access link

A link from Pc to switch is called as access link or A link that is part of only one

VLAN. Therefore, a port connecting to an access link can be a member of only one

VLAN. And the mode of port is called as access mode.

• Trunk link

A link from switch to switch or switch to router is called as trunk link. A 100

Mbps or 1000 Mbps point-to-point link that connects switches or routers, and carries

frames of different VLANs . Therefore, a port connecting to a trunk link can be a member

of multiple VLANs. All VLANs are configured on a trunk link by default. VLAN

Trunking, by making use of frame tagging, allows traffic from different VLANs to

transmit through the same Ethernet link (trunk link) across switches.

VLAN Trunking identifies the VLAN from which a frame is sent by tagging the

frame with the source VLAN ID (12-bit long). This feature is known as frame tagging or

frame identification. When there are multiple switches then we have to use trunk links to

connect one switch with other. If we are not using trunk links then we have to connect

one cable from each vlan to the corresponding vlan of the other switch.

With frame tagging, a switch knows which ports it should forward a broadcast

frame (forward out the ports which have the same VLAN ID as the source VLAN ID). It

also knows which bridge table it should use for forwarding an unicast frame (since a

separate bridge table is used for each VLAN).

A frame tag is added when a frame is forwarded out to a trunk link, and is

removed when the frame is forwarded out to an access link. Therefore, any device

attached to an access link is unaware of its VLAN membership.

Commands to create Vlan

Switch#vlan database

Switch(vlan)#vlan <no.> [name <name of vlan>]

Switch(vlan)#exit

Commands to configure ports for a Vlan

By default, all ports are member of single vlan that is Vlan1. we can change vlan

membership according to our requirement.

Switch(config)#interface <type> <no.>

Switch(config-if)#switchport access vlan <no.>

Switch(config-if)#exit

Commands to configure multiple ports in a vlan

Switch(config)#interface range <type> <slot/port no. (space)–(space) port no.>

Switch(config-if)#switchport access vlan <no.>

Switch(config-if)#exit

Example: - Suppose we want to add interface fast Ethernet 0/10 to 0/18 in vlan5

Switch(config)#interface range fastethernet 0/10 – 18

Switch(config-if)#switchport access vlan 5

Switch(config-if)#exit

To display mac address table

Switch#show mac-address-table

Vlan Mac address type ports

20 00-08-a16-ab-6a-7b dynamic fa0/7

To Display Vlan and port membership

Switch#show vlan brief

Command to make Trunk link

Switch(config)#interface <type> <type number>

Note :- Trunk mode should not be a member of any vlan port.

3.17.1.2 Vlan Trunking Protocol (VTP)

With the help of VTP, we can simplify the process of creating Vlan. In multiple

switches, we can configure one switch as VTP server and all other switches will be

configured as VTP client. We will create Vlans on VTP server switch. The server will

send periodic updates to VTP client switches. The clients will create Vlans from the

update received from the VTP server.

VTP Operation

• VTP advertisements are sent as multicast frames.

• VTP servers and clients are synchronized to the latest revision number.

• VTP advertisements are sent every 5 minutes or when there is a change.

VTP Modes

• VTP server mode

By default all the switches in this mode are in server mode. VTP server is a

switch in which we can create, delete or modify Vlans.yhe switch in this mode

forwords the vlans to next switch. The server will send periodic updates for VTP

clients.

• VTP client mode

On VTP client, we are not able to create, modify or delete Vlans. The switch

in this mode creates the vlans that are received from server mode switch.The client

will receive and forward vtp updates. The client will create same Vlans as defined in

vtp update.

• VTP Transparent mode

Transparent is a switch, which will receive and forward VTP update. It is able

to create, delete and modify Vlans locally. A vlan created in this mode cannot be

forworded into next switch. A transparent will not send its own VTP updates and will

not learn any information from received vtp update.

VTP configuration

At Switch 1:

• Creat vlan

• Port assignment

• Trunk port

• Switch vtp

Switch(config)#vtp mode server

Switch(config)#vtp domain cisco

Switch(config)#vtp password sun

At switch 2:

Switch(config)#vtp mode server

Switch(config)#vtp domain cisco

Switch(config)#vtp password sun

At switch 3:

Switch(config)#vtp mode server

Switch(config)#vtp domain cisco

Switch(config)#vtp password sun

Fig 27 : VTP Configuration

To see all the configurations

Switch#show vtp password

Switch#show vlan brief

Switch#show vtp status

• Vtp version

• Vtp domain

• Vtp mode

• Vtp pruning

• Vtp reusion number

• Maximum vlan supporting

• Total no. of vlans

VTP Pruning

Pruning is the VTP feature through which a trunk link can be automatically

disable, for a particular Vlan if neighbor switch does not contain ports in that Vlan. Vlan1

is not prun eligible.

• Increases available bandwidth by reducing unnecessary flooded traffic

• Example: Station A sends broadcast, and broadcast is flooded only toward

any switch with ports assigned to the red VLAN

Command to configure VTP Pruning

We have to use only one command on VTP server for VTP Pruning.

Switch#configure terminal

Switch(config)#vtp pruning

Switch(config)#exit

Fig 28 : VTP Pruning

Spanning Tree Protocol

When we connect multiple switches with each other and multiple path exist from

one switch to another switch then it may lead to the switching loop in the network.

Multiple paths are used to create redundancy in the network. STP is only required when

multiple path exist then there is possibility of loop in n/w.

Problems that occur with redundancy path

(i) Multiple copies of the frame will be received by destination.

(ii) Frequent changes in the mac address table of switch.

(iii) A mac address may appear at multiple ports in a switch.

(iv) Packets may enter in the endless loop.

Spanning Tree Protocol will solve this problem by blocking the redundancy

interface. So that only one path will remain active in the switches. If the primary path

goes down then disabled link will become enable and data will be transferred through that

path.

Spanning Tree Protocol Basics

• Spanning Tree Protocol or STP (IEEE 802.1d) is used to solve the looping

problem.It runs on bridges and switches in a network. It implements a Spanning

Tree Algorithm (STA), which calculates a loop-free topology for the network.

• STP ensures that there is only one active path between any two network segments

by blocking the redundant paths. A redundant path is used only when the

corresponding active path failed. It is not used for load-balancing.

• Because STP solves the looping problem by blocking one or more links in a

network, the frames traveling between some source / destination devices may not

be able to use the shortest physical path.

• Bridges exchange STP information using messages called Bridge Protocol Data

Units (BPDUs) through Layer 2 multicast.

3.18 Wi-Fi (WIRELESS FIDELITY)

The term "Wi-Fi" suggests "Wireless Fidelity", compared with the long-

established audio recording term "High Fidelity" or "Hi-Fi". The term "Wi-Fi", first used

commercially in August 1999. Wi-Fi is an IEEE standard 802.11.

3.18.1 Wireless LAN

Wi-Fi is also known as wireless LAN. The name of a popular wireless

networking technology that uses radio waves to provide wireless high-speed Internet and

network connections. "Wi-Fi works with no physical wired connection between sender

and receiver by using radio frequency (RF) technology, a frequency within the

electromagnetic spectrum associated with radio wave propagation. When an RF current is

supplied to an antenna, an electromagnetic field is created that then is able to propagate

through space.

The Typical Range of a Wi-Fi LAN

The range of a home Wi-Fi LAN depends on the wireless access point (WAP) or

wireless router being used. Factors that determine a particular WAP or wireless router's

range are:

• the specific 802.11 protocol employed

• the overall strength of the device transmitter

• the nature of obstructions and interference in the surrounding area

A general rule of thumb in home networking says that 802.11b and 802.11g

WAPs and routers support a range of up to 150 feet (46 m) indoors and 300 feet (92 m)

outdoors. Another rule of thumb holds that the effective range of 802.11a is

approximately one-third that of 802.11b/g.

Obstructions in home such as brick walls and metal frames or siding greatly can

reduce the range of a Wi-Fi LAN by 25% or more. Because 802.11a employs a higher

signalling frequency than 802.11b/g, 802.11a is most susceptible to obstructions.

Interference from microwave ovens and other equipment also affects range. 802.11b and

802.11g are both susceptible to these.

3.18.2 Wireless Standards

The different wireless standards that are used for IEEE 802.11 standard are

Fig 29: IEEE 802.11 Standards

802.11

It was released in year 1997. The standard was original of 802.11. the max. data

rate of this is 2Mbps and frequency of this is 2.4GHz and can cover upto 46m.

802.11a

It was modified in year 1999. this is improved version of original standard.

Operates at the frequency of 5GHz, which is less crowded than 2.4GHz where telephones

and microwaves may cause interference. Although the speed is up to 54Mbps, the range

is only up to 75 feet or distance covered is 46m. 802.11a standard is incompatible with

both 802.11b and g because it operates at a different frequency.

802.11b

This standard was released in 1999. Operates on the 2.4GHz frequency band and

can transmit data at speeds of up to 11Mbps within a range of up to 100-150 feet or a

distance of 90m.Wireless range can be affected by reflective or signal-blocking obstacles,

such as mirrors, walls, devices and location, whether indoors or outdoors.

802.11g

This standard was released in 2003. The max. data rate for the standard is 54Mbps.

It supports a frequency range of 2.4GHz, covers a distance of 90m.

802.11n

The latest version of IEEE 802.11 standard that is still in progress of

development. The next generation of high-speed wireless networking, capable of

delivering the range and capacity to support today's most bandwidth-hungry applications

like streaming high definition video, voice, and music. Wireless-n is based on MIMO

(Multiple Input, Multiple Output) technology, which uses multiple radios to transmit

multiple streams of data over multiple channnels.

Operates in two modes of frequency 2.4GHz and 5.6GHz frequency band and

can transmit data at speeds of up to 11Mbps within a range of up to 100-150 feet .

Wireless range can be affected by reflective or signal-blocking obstacles, such as mirrors,

walls, devices and location, whether indoors or outdoors.

Wi-Fi is supported by many applications and devices

• video game consoles

• home networks

• PDAs

• mobile phones

• major operating systems

• other types of consumer electronics

3.18.3 Wireless Security

A common but unproductive measure to deter unauthorized users is to suppress the

AP's SSID broadcast, "hiding" it. This is ineffective as a security method because the

SSID is broadcast in the clear in response to a client SSID query. Another unproductive

method is to only allow computers with known MAC addresses to join the network.

MAC address are easily spoofed. If the eavesdropper has the ability to change his MAC

address, then he may join the network by spoofing an authorized address.

Wired Equivalent Privacy (WEP) encryption was designed to protect against casual

snooping, but is now considered completely broken. Tools such as AirSnort or aircrack

can quickly recover WEP encryption keys.

To counteract this in 2002, the Wi-Fi Alliance blessed Wi-Fi Protected Access (WPA)

for wireless security. Though more secure than WEP, it has outlived its designed lifetime,

has known attack vectors and is no longer recommended.

In 2004 the full IEEE 802.11i (WPA2) encryption standards were released. If used with a

802.1X server or in pre-shared key mode with a strong and uncommon passphrase WPA2

is still considered secure, as of 2009.

4. CONCLUSION

General Conclusion

Computer Networking is a very vast project in the present developing era of

electronics and communication. Now a days, computers are used in a wider range. All the

organizations are using multiple computers within their departments to perform their day

to day work. Computer network allows the user to share data , share folders and files with

other users connected in a network. Computer Networking has bound the world in a very

small area with it wide networking processes like LAN, MAN, WAN.

Applications

• Communication Field

• Industries

• Medical Field

• Rearch Field

• Organisations

• School

• Colleges

REFRENCES

• www.goole.com

• www.jetkinginfotrain.com

• www.microsoft.com

• www.nythimes.com

• www.digitech-engineers.com

• Network Essentials module

• 4-in-1 MCSE study material

• Introduction to Window Server2003

• CISCO Cretified Network Associate

• Faruk Husain