BY

AMIT UDHWANI

ABOUT CISCO :-

Cisco is founded in 1984 by Sandy Lerner

and Len Bosack.

Cisco goes public in 1990 and is listed on

the NASDAQ stock exchange.

More than 71500 employees.

Nearly 70000 channel partners.

More than 30000 CCIE professional.

CISCO CERTIFICATIONS PATH

Certification

Path

Entry

Level

Associate

Level

Professional

Level

Expert

Level

Routing &

Switching

CCENT CCNA R&S CCNP R&S CCIE R&S

Secuirty CCENT CCNA Security CCNP Security CCIE Security

Voice CCENT CCNA Voice CCNP Voice CCIE Voice

Wireless CCENT CCNA Wireless CCNP Wireless CCIE Wireless

Data Center CCENT CCNA Data

Center

CCNP Data Center CCIE Data center

CCNA ROUTING & SWITCHING CONTENT:-

• ROUTING

(1) Basics of Routing

(2) CDP

(3) Routing Protocols

(a) Rip

(b) Eigrp

(c) Ospf

(4) Nat (Network Address Translation)

(5) Dhcp (Dynamic Host Configuration Protocol)

(6) Frame-Relay

. SWITCHING

(1) Basics of Switching

(2) Vlans

(3) Switching Protocols

(a) STP

(b) VTP

(4)Etherchannel

ROUTER:-

• Router is a layer 3 device.

• Router is used to connect two

different network.

• Router used as switch, firewall.

• Router also do packet filtering.

• Router always choose the best

path to route any packet.

• Router suppot unicast, multicast

but broadcast is not supported by routers.

CDP(CISCO DISCOVERY PROTOCOL)

• CDP protocol is cisco proprietry

protocol used by cisco device only.

• Cisco router and switch exchange the

cdp to each other in every 60 secound.

• CDP packet is used to show all the

information about cisco devices.

• By default every cisco device exchange

the cdp packets if we want to stop then

use command:-

router(config)# Interface serial 0/0

router(config-router)# No cdp e

vnable

Routing

• The process of moving a packet of data from source to

destination and from destination to source is called

routing.

• A router may create or maintain a table of the available

routes and their conditions and use this information

along with distance and cost algorithms to determine

the best route for a given packet.

• Packet may travel through a number of network points

with routers before arriving at its destination.

• There are two types of routing:-

(1) Static Routing.

(2) Dynamic Routing.

Dynamic Routing Protocol

DISTANCE VECTOR ROUTING

PROTOCOL

LINK STATE ROUTING

PROTOCOL

1. Entire routing table is sent as an update.

2. Send periodic update (Every fixed interval of time

at every 30 secound).

3. Update are broadcast.

4. Update are sent to directly connected neighbour

only.

5. Router donot have end to end visibility of entire

network.

6. Routing loops may be exist.

1. Update are incremental.

2. Updates are triggered not periodic.

3. Update are multicast.

4. Update are sent to entire network.

5. Router have visibility of entire network.

6. No routing loop exist.

RIP (Routing Information Protocol)• Rip is a Dynamic Routing Protocol.

• Rip is a Distance Vector Routing Protocol.

• It developed for smaller network.

• Rip calculate the best route based on hop count.

• Maximum numbers of hop is 15 after that it considered as

unrechable.

• Rip require less cpu power & ram.

• Rip uses 30 secound to update interval by default.

• Two version available in rip first is RIP V 1 and secound is

RIP V 2.

RIP VERSIONS

RIP VERSION 1 RIP VERSION 2

1. It support classfull routing.

2. Vlsm not supported.

3. Update message is sent to broadcast

address 255.255.255.0.

4. No authentication support.

5. Rip version 1 donot support manual

summerization because it broadcast all the

routes on 255.255.255.255 without any subnet

information.

1. It support classless routing.

2. Vlsm Supported.

3. Update message is sent to multicast address

224.0.0.9.

4. Support plaintext and MD5 authentication.

5. Rip version 2 support manual

summerization.

Routing Information Protocol Timers:-

1. Update Timer:-

In rip update timers is 30 secound by

default. It means that after every 30 sec rip send

thier whole update to thier neighbour router.

2. Hold down timer:-

In rip hold down timer is 180 secound

by default. It means that router hold the rip routes

only for 180 after 180 secound route will be invalid

but it will remain in routing table.

3. Flush Timer:-

In rip flush timer is 240 secound by

default. It means that router hold any route for 240

secound after 240 secound the route will be flushed

out from routing table.

RIP CONFIGURATION

COMMAND COMMAND'S PURPOSE

Rtr(config)#router rip Enables RIP routing process

Rtr(config-router)#network ip address Associates a network with a RIP routing process

Rtr(config)#Router rip

Rtr(conifg-router)# timer basic 30 180 180 240

used to change timers in rip protocol.

Rtr#show ip route rip Used to display Rip routes.

Rtr#show ip protocol Used to display protocol information.

EIGRP(Enhanced Interior Gateway Routing

Protocol)• It is an advanced distance vector routing

protocol.

• EIGRP is used on a router to share routes

with other routers within the same

autonomous system.

• Basic values in eigrp:-

AD- 90, 170

Protocol- 88

Max hop count- 255, By default- 100

• Eigrp choose thier best route by using the

metric values such as bandwidth, delay,

load reliability.

RIP(Routing Information

Protocol)

EIGRP(Enhanced Interior

Gateway Routing Protocol)

1. Distance vector routing proctocol.

2. Metric - hop count limited to 15.

3. Update - periodic (send every 30

sec).

4. Max hop count- 15

5.Update- Broadcast (version 1)

Multicast(version 2)

1. Advanced distance vector routing

protocol.

2. Metric - Bandwidth, Delay, Load,

Reliability.

3. Update- Triggered.

4. Max hop count - 255, 100

5. Update - Multicast

Eigrp Packets:-

• HELLO:-

Hello packet is use send to discover

the neighbour.

In hello packet router send thier parameters to

other router after every 5 secound.

• UPDATE:-

Eigrp send two types of update

packets.

1. FULL UPDATE PACKET:- First

time eigrp send thier full topology information

in update packet.

2. PARTIAL UPDATE PACKET:-

After exchanging full update eigrp send partial

update .

• ACK:-

Eigrp send acknowledgement when it

recieve any packet from other router.

EIGRP NEIGHBORSHIP CONDITION:-

• Both router use same AS no.

• Metric weight should be same

on both side.

• Id authentication is enable

then configuration of

authentication is same on both

side.

• Router must have to able to

send/ recieve ip packet to one

another.

• Interface ip address must be

in same subnets.

Configuration of Eigrp:-

COMMAND COMMAND'S PURPOSE

Rtr(config)#router eigrp as no. Enables EIGRP routing process

Rtr(config-router)#network ip address Associates a network with a EIGRP routing process

Rtr#debug ip eigrp packets used to view real time EIGRP routing updates

Rtr(config-router)#show ip eigrp topology Used to display fs and successor in eigrp.

Rtr#show ip eigrp topology all-links Used to display all routing links in eigrp process.

OSPF(OPEN SHORTEST PATH FIRST)• Ospf is a linked state routing protocol.

• In ospf every switch knows the whole topology

and information about connected router.

• Ospf create Graph and run the shortest path

first algorithm to choose the best path.

• To make ospf scalable we devide ospf process

into many areas.

• In ospf area 0 is called backbone area and

other areas are called non-backbone area.

• In ospf all areas will communicate via area 0.

OSPF PACKETS:-HELLO:-

A HELLO packet is a special packet (message) that is sent

out periodically from a router to establish and confirm network

adjacency relationships.

DBD:-

This packet is used to check if the LSDB between 2 routers

is the same.

LSR:-

This packet is used to send request for database from its

neighbors.

LSU:-

This packet is used to carry the information of database from

one router to another.

LSACK:-

This packet is used to give acknowledgement to thier

neighbor router.

OSPF NEIGHBORSHIP STATES:-• DOWN:-

When routers are down or ospf not run.

• INIT:-

when we run ospf on routers and they will send hello

packet to each other and exchange thier parameters and

this proces is called initilization process.

• TWO WAYS:-

when routers exchange thier hello packet and

parameters are matched on both routers and they becomes

neighbors then we can say that they are in two ways state.

• EXSTART:-

In exstart process both router decide who will start

data exchange process and who will end data exchange

process. They will go in master and slave election . one

router will become master and other will become slave.

OSPF NEIGHBORSHIP STATES (Cont....)

• EXCHANGE:-

In exchange state router send

DBD packet which contain LSID i.e. They

only exchange header of database. Router-

id is become LSID.

• LOADING:-

In loading state they exchange

thier data base with each other. With the

help of LSR, LSU and LSACK packet.

• FULL:-

When all router exchange thier data

base then they are in full state.

OSPF CONFIGURATIONS:-

COMMAND COMMAND'S PURPOSE

Rtr(config)#router ospf process no. Enables OSPF routing process

Rtr(config-router)#network ip address Associates a network with a OSPF routing process

Rtr#debug ip OSPF packets used to view real time OSPF routing updates

Rtr(config-router)#show ip ospf database Used to display ospf information.

Rtr#show ip ospf Used to display all routing links in eigrp process.

ACL(Access Control Lists)• ACLs are lists of conditions that are applied to

traffic traveling across a router's interface.

• ACLs can be configured at the router to control

access to a network or subnet.

• There are two types of ACLs

1. Standard

2. Extended

• ACL Limit network traffic and increase network

performance.

• If ACLs are not configured on the router, all

packets passing through the router will be allowed

onto all parts of the network.

NAT(Network Address Translation

• Network address translation is as the name suggests. It

translates one type of address into another. Lets take an

example. I have a network running with 172.16.1.0/24 as my

IP subnet. I want it to be converted/translated to

192.10.10.0/24 network when leaving a router interface.

• NAT will maintain a table of entries specifies which

172.16.0.0/24 addresses have been converted to

192.10.10.0/24 addresses so that when the return packet

comes it will be send to the right user. NAT translation will

be based on host basis .

• NAT is used to overcome the shortage of public IP space.

We can use private IP in our internal network and can use a

pool of public addresses when going to the internet.

DHCP(dynamic host configuration protocol)

• A DHCP server listens for DHCP requests and responds

by issuing an IP address. A DHCP server is built into most

home routers, and will assign a private network address

usually in 192.168.0.0/16 to any device that requests one.

• DHCP client starts by broadcasting the DHCP DISCOVER

packet. The broadcast is received by the DHCP Server(s),

which in turn replies with the DHCP OFFER message.

• The DHCP client may receive multiple DHCP OFFER

messages, however it chooses only one DHCP OFFER

message based on the policy configured in the DHCP

Client. Usually its on the first come first serve basis.

• The request is then sent to dhcp server and dhcp server

send ip address from its pool in ack packet.

FRAME RELAY

• Frame Relay is packet-switched

technology.

• Frame relay works on layer 2 technology.

• Frame relay use serial links.

• Frame relay save the cost.

• We can also save address space by

using frame relay.• DLCI:-

Frame relay use DLCI no. It is always

unique for new connection.• LMI:-

Frame relay send lmi packet to every

one as keep alive message.

SWITCH

• switch is a layer 2 device.

• switch works on mac address.

• It has single broadcast domain but

we can change the broadcast domain

by creating vlan.

• Single broadcast domain means all

the interfaces of switch are the

member of same vlan .

• By default all interface are in vlan 1.

• Switch is used to connect many users

and routers.

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 called Inter

Vlan Communication.

VTP(Vlan Trunking Protocol)

• Vtp stands for vlan trunking protocol which

is used to share vlan information with each

other.

• lets take an example if we have 100

switches and we need to configure three

vlans called as vlan 10 20 and 30 the initial

way to do it is to go to each and every

switch and configure vlans which becomes

a very hectic task and there are also a

chances for misconfigurations.

• In these cases vtp is used vtp is configured

on all the switches. One switch is kept in

vtp server mode and other in vtp client

mode. The vlans are then configured on

the server switch it immediatly deflects to

all the other 99switches which reduces the

administrative load.

STP(SPANNING TREE PROTOCOL)• In switching spanning tree protocol

is used to control the loop.

• By default all switch forward the

BPDU message to each other. On

the basis of bpdu message switch

will decide thier Root Bridge who

control the stp process in vlan.

• Cisco switch run per vlan spanning

tree protocol.

• In spanning tree protocol every

switch have one root port except

root bridge.

• Root port is always the best path to

reach the root bridge for non-root

bridge switches.

ETHERCHANNEL

• A Cisco technique that provides the ability

to negotiate to bundle multiple physical

links into a single, logical, higher speed

link.

• Two types of protocol is used to form

etherchannel.

(1) LACP:-

Link Aggregation Control

Protocol, is used to dynamically build an

EtherChannel. There are different modes of

LACP. It can bundle 16 link at a time.

(2) PAGP:-

Port Aggregation Protocol is used

to achieve the same goal as LACP. But it can

bundle 8 links at a time.

ETHERCHANNEL (cont....)• LACP MODE:-

1. Active:

The active end of the group sends out a LACP frame and initiates the negotiation to form the

EtherChannel. Both ends could be active and the result would be the same.

2. Passive:

Passive Mode does not initiate the negotiation. It just responds to LACP packets initiated by

other end. So if both ends were passive, the EtherChannel would not be formed.

• PAGP MODE:-

1. Desirable:

In this mode, the negotiation will be initiated by sending the special frames to form

EtherChannel with the other end.

2. Auto:

In this mode, negotiation is not initiated. It only responds to the special frames received for

negotiation form the other end. So, if both ends are in Auto mode, EtherChannel would not be formed.