Network Addressing

Tehran Institute of Technology CISCO CCNA Instructor: M. Naslcheraghi

Email: M.naslcheraghi@gmail.com

Resume: http://www.teleinfra.net/download/cv.pdf Summer, 2011

Tehran Institute of Technology

Describe the purpose of an IP Address and Subnet Mask and how they are used on the Internet

Describe the types of IP Addresses available

Describe the methods of obtaining an IP Address

Describe the use of NAT on a home or small business network using an ISR

Each host needs IP to communicate

Logical address

Assigned to the NIC ◦ Computers, network printer, router interfaces

Remember ◦ Packet has source & destination IP

Complete Packet Tracer 5.1.1.2 “Connecting to a Web Server Using IP”

Logical (not physical like MAC)

IPv4

32 bits, 4 octets ◦ 8 bits in each octet

◦ 11111111.10101010.11001100.00100101

Written in decimal ◦ 192.101.28.36

Value in each octet from 0-255 ◦ That’s a total of 256 numbers.

Add up the values of the binary 1’s

128 64 32 16 8 4 2 1

1 0 0 1 1 1 0 0 ◦ 156

11100101 ◦ 229

How to Do Conversions Handout

Binary & Decimal Conversions Practice

Binary Game in Curriculum 5.1.2.3

Network portion ◦ Identifies network to the router ◦ Router cares about this part

Host portion ◦ Identifies the specific host ◦ Router doesn’t care about this part Hierarchical Addressing

192.175.36.9

Subnet Mask ◦ Helps router decide which network packet is on

◦ Helps show which part of IP is network & host

◦ 32 bits

◦ 192.168.6.5 255.255.255.0

Binary 1’s - ID the network portion

Binary 0’s - ID the host portion

199.81.210.17

255.255.255.240

What network does this belong to?

SM helps tells us how many hosts are on that network ◦ 255.255.255.00000000

◦ Binary 0= identifies # of hosts on that network

◦ 8 ZEROS is 28=256

◦ Subtract 2 for useable number

Unusable:

00000000 (.0) is the network ID

11111111 (.255) is the broadcast address for a network

Total Useable is 254

SM 255.255.255.128 ◦ 128= 10000000

◦ 27= 128-2 is 126 hosts

SM 255.255.255.224 ◦ 224= 11100000

◦ 25= 32-2 is 30 hosts

SM 255.255.240.0 ◦ .240.0= 11110000.00000000

◦ 212= 4096-2 is 4094 hosts

One PC is 192.168.18.107 255.255.255.0 ◦ What is network does it belong to?

◦ How many useable hosts?

◦ Give PC’s addresses.

Hex= MAC address

0-9, A-F (10-15)

AB

5.1.4 Lab (No Calculator)

Homework- Decimal/Hex/Binary Conversion

1. Which version IP addresses are we dealing with? ◦ IPv4

2. How many bits in an IP address? ◦ 32

3. How many octets in an IP address? ◦ 4

4. Which part of this address is the host portion? 199.81.71.6 ◦ 6

1. Which network does this belong on? 201.14.6.5 255.255.255.0 ◦ 201.14.6.0 network

2. How many total hosts can be on that network? Useable? ◦ 256

◦ 254, why?

Class A ◦ Large organizations

◦ 1-127

◦ Default SM= 255.0.0.0 One octet for network, 3 octets for hosts

◦ How many hosts available? 224= over 16 million

◦ 10.52.33.7

◦ N.H.H.H

◦ 255.0.0.0

◦ 120.111.99.87

15.7.92.5 255.0.0.0

15= Class A Default SM for Class A= 255.0.0.0 Network portion of address= 15. Host portion= .7.92.5 Network ID= 15.0.0.0 ◦ All zero’s in the host portion

Broadcast address= 15.255.255.255 ◦ All binary one’s in the host portion

Class B ◦ Medium organizations

◦ 128-191

◦ Default SM= 255.255.0.0 Two octets for network, 2 octets for hosts

◦ How many hosts available? 216= over 65,000

◦ 130.52.33.7

◦ N.N.H.H

◦ 255.255.0.0

◦ 185.111.99.87

167.101.52.36 255.255.0.0

167= Class B Default SM for Class B= 255.255.0.0 Network portion of address= 167.101 Host portion= .52.36 Network ID= 167.101.0.0 ◦ All zero’s in the host portion

Broadcast address= 167.101.255.255 ◦ All binary one’s in the host portion

Class C ◦ Small organizations

◦ 192-223

◦ Default SM= 255.255.255.0 Three octets for network, 1 octet for hosts

◦ How many hosts available? 28= 256-2 (254 useable)

◦ 199.52.33.7

◦ N.N.N.H

◦ 255.255.255.0

◦ 220.111.99.87

210.44.200.89 255.255.255.0

210= Class C Default SM for Class C= 255.255.255.0 Network portion of address= 210.44.200 Host portion= .89 Network ID= 210.44.200.0 ◦ All zero’s in the host portion

Broadcast address= 210.44.200.255 ◦ All binary one’s in the host portion

Class D & E not for commercial use ◦ D is multicast (one to a group) ◦ 224.0.0.0- 239.255.255.255

All 0’s in host portion(s) = network ID All 1’s in host portion(s)= broadcast CAN NOT USE THOSE FOR HOSTS!

Address

Class

Address Range

A 10.0.0.0- 10.255.255.255

B 172.16.0.0- 172.31.255.255

C 192.168.0.0- 192.168.255.255

Some addresses are reserved & can not be routed across Internet

You can have a public IP for network/servers & private for hosts inside ◦ Saves IP addresses

If host does not connect DIRECTLY to Internet, it can have a private IP

Router BLOCKS private IP’s

Great Security!!! ◦ Private IP’s can not be seen from Internet

127.0.0.0 range is reserved for loopback testing

One-to-one or Source to destination

One-to-all or Source to all in segment

All hosts will look at it

All 1’s in host portion(s) of address

Broadcast IP & MAC (all F’s)

Default Broadcasts ◦ A- 10.255.255.255 255.0.0.0

◦ B- 172.16.255.255 255.255.0.0

◦ C- 192.168.1.255 255.255.255.0

One-to-group

Class D 224.0.0.0- 239.255.255.255

Multicast MAC begins with 01-00-5E

Where is it used? ◦ Gaming

◦ Distance learning

Unicast, Multicast, or Broadcast

Command Prompt ◦ Netstat –e

◦ Do this every 10 seconds

◦ Pay attention to non-unicast packets

1. 160.50.23.6 255.255.0.0; What network is this on? ◦ 160.50.0.0

2. Which default SM has the most hosts? ◦ Class A 255.0.0.0 ◦ Over 16 million!

3. How many useable hosts in a Class C? ◦ 254

4. 220.101.5.90 255.255.255.0; What network is this on? ◦ 220.101.5.0

1. What are the private IP addresses? ◦ 10, 172.16-172.31, 192.168.

2. What is the MAC broadcast frame in hex? ◦ FF-FF-FF-FF-FF-FF

3. What is the MAC for a multicast? ◦ 01-00-5E

4. One to one communication is… ◦ Unicast

5. To send a unicast message, which addresses do you need? ◦ Source & dest. IP & MAC

Static ◦ Manually type in IP

Address ◦ Good for printers or

servers Devices people access

all the time

You wouldn’t want their address changing!

◦ Good documentation!!!!

Dynamic ◦ Assigned auto by

DHCP server

◦ Assigns IP, SM, DG, more

◦ Good for larger networks or with mobile/new devices

◦ Leased addresses

Admins have a pool of IP addresses ◦ DHCP assigns from the pool

SOHO routers usually have DHCP

Medical field- ◦ Legal requirement

◦ Must track who is on machine

◦ DHCP server assigns & keeps log of users

How you get on the net in a hotel, Starbucks, or BK

Either dedicated server or mixed in another device ◦ From ISP or on your ISR

192.168.1.1

Packet

Tracer Lab

5.3.3.3

1. Which addresses does a host use to discover a DHCP server? ◦ 255.255.255.255 ◦ FF-FF-FF-FF-FF-FF

2. Who sees that? Who responds? ◦ All on the segment ◦ The DHCP server

3. What happens to a PC’s IP when you shut down? ◦ Goes back to the DHCP pool of addresses

Directly ◦ 1 PC to a modem

◦ PC gets address from ISP

ISR ◦ Modem to ISR

◦ Internal PC’s get addresses from ISR

Gateway Device ◦ ISR & Modem in one

◦ Internal gets private IP’s

Translates private into public addresses

Prevents external from seeing internal

A private (local) source IP address is translated to a public (global) address. ◦ The process is reversed for incoming packets.

◦ The integrated router is able to translate many internal IP addresses to the same public address, by using NAT.

1. Which address does the PC

need to access the Internet? ◦ Default gateway address of the ISR

2. Which devices translates NAT? ◦ ISR

Reference: Cisco Networking Academy