sypcnsa department2007 summer youth program: internal protocols: rip & igrp

SYPCNSA Department 2007

Summer Youth Program: Summer Youth Program: Internal Protocols: Internal Protocols:

RIP & IGRPRIP & IGRP


To route a router need to know:– Remote Networks

– Neighbor Routers

– All Possible routes to remote network

– The absolute best route to all remote networks

– Maintain and verify the routing information

What is Routing?

C B AD


Basic Path Selection

What interface will the router send out a packet if it has destination address of 10.10.10.18?


Basic IP Routing

172.16.1.0

BA

172.16.2.0

172.16.2.2

172.16.1.2172.16.2.1 172.16.1.1

e0 e0

>ping 172.16.1.2>ping 172.16.1.2

B

172.16.3.1 172.16.3.2

s0s0

Host A

Host B


Routing/PDU Example:Host A Web browses to the HTTP

Server….

3. The destination port number in a segment header will have a value of __

1. The destination address of a frame will be the _______________________

2. The destination IP address of a packet will be the IP address of the ________________________________


Routing/PDU Example:Host A Web browses to the HTTP

Server….

3. The destination port number in a segment header will have a value of 80

1. The destination address of a frame will be the Ethernet 0 on Lab A

2. The destination IP address of a packet will be the IP address of the NIC of the HTTP server


172.16.3.2

SO

Static Routes

172.16.1.0

B172.16.3.1

A B

Stub Network

172.16.2.0

SOA

Routes must be unidirectional


ip route remote network

[mask]

{address|interface}

[distance]

[permanent]

Router(config)#ip route remote_network mask next_hop

Static Route Configuration


ip route 172.16.1.0 255.255.255.0 172.16.3.2orip route 172.16.1.0 255.255.255.0 s0

Static Route Example

172.16.3.2

SO

172.16.1.0

B172.16.3.1

A B

Stub Network

172.16.2.0

SO


Default Routes

172.16.3.2

SO

172.16.1.0

B172.16.3.1

A B

Stub Network

172.16.2.0

SO

ip route 0.0.0.0 0.0.0.0 172.16.3.1 ip classless


• Routing protocols are used between routers to: – Determine the path of a packet through a network– Maintain routing tables– Examples?

• Routed protocols are:– Assigned to an interface– Once the path is determined by the Routing protocol, determines

method of delivery– Examples?

Routing vs. Routed


Autonomous System 1 Autonomous System 2

IGPs: RIP, IGRP EGPs: BGP

Routing Protocols

•An autonomous system is a collection of networks under a common administrative domain.

•IGPs operate within an autonomous system.

•EGPs connect different autonomous systems.


Classful Routing Overview

Classful routing protocols do not include the subnet mask with the route advertisement.

– Within the same network, consistency of the subnet masks is assumed.

– Summary routes are exchanged between foreign networks.

– Examples of classful routing protocols:• RIP Version 1 (RIPv1)• IGRP


Classless Routing Overview

Classless routing protocols include the subnet mask with the route advertisement.

– Classless routing protocols support variable-length subnet masking (VLSM).

– Summary routes can be manually controlled within the network.

– Examples of classless routing protocols:

• RIP Version 2 (RIPv2)

• EIGRP

• OSPF

• IS-IS


IGRPAdministrative Distance=100

Router D

Router BRouter A

Router C

RIPAdministrative Distance=120

Default Administrative DistanceDirectly Connected: 0Static Route: 1RIP: 120IGRP: 100EIGRP: 90OSPF: 110

Administrative Distance


C B AD

RoutingTable

RoutingTable

RoutingTable

RoutingTable

RoutingTable

RoutingTable

RoutingTable

RoutingTable

Distance—How farVector—In which direction

Distance—How farVector—In which direction

Distance vector algorithms do not allow a router to know the exact topology of an internetwork.

All routers just broadcast their entire routing table out all active interfaces on periodic time intervals

Distance Vector


Discovering RoutesDiscovering Routes


Routing Tables PopulatedRouting Tables Populated


Routing Loops


Router Loops


64kbps

T1

T1 T1

– Hop count metric selects the path, 16 is unreachable– Full route table broadcast every 30 seconds– Load balance maximum of 6 equal cost paths (default = 4)– RIPv2 supports VLSM and Discontiguous networks

RIP Overview


Router(config)#router rip

Router(config-router)#network network-number*

network 172.16.0.0network 192.168.10.0

router RIPnetwork 172.16.0.0network 10.0.0.0

router RIP

*Network is a classful network address.

Every device on network uses the same subnet mask

172.16.10.0 192.168.10.010.3.5.0

RIP Routing Configuration


RIP Version 2

• Allows the use of variable length subnet masks (VLSM) by sending subnet mask information with each route update

• Distance Vector – same AD, and timers.• Easy configuration, just add the command

“version 2” under the router rip configuration

router ripnetwork 10.0.0.0version 2


Discontiguous Addressing

• Two networks of the same classful networks are separated by a different network address

192.168.10.0/24

10.1.1.0/24192.168.10.0/24

– RIPv1 and IGRP do not advertise subnet masks, and therefore cannot support discontiguous subnets.

– OSPF, EIGRP, and RIPv2 can advertise subnet masks, and therefore can support discontiguous subnets.


Passive Interface

Maybe you don’t want to send RIP updates out your router interface connected to the Internet. Use the passive-interface command:Router(config)#router rip

Router(config-router)#passive-interface serial0

This allows a router to receive route updates on an interface, but not send updates via that interface

S0 GatewayInternet

Updates

XX


Verifying RIP

Router#show ip protocols

Router#show protocols

Router#show ip route

Router#debug ip rip

Router#undebug all (un all)


IGRP• Interior Gateway Routing Protocol - Cisco Proprietary• Uses bandwidth and delay of the line by default to select best path

AutonomousSystem

Router D

Router BRouter A

Router C

Requires Autonomous System number for activation


IGRP vs. RIP

• The important IGRP characteristics are as follows:– More scalability than RIP

– Fast response to network changes

– Sophisticated metric

– Multiple-path support


Router(config)#router igrp autonomous-system

Router(config-router)#network network-number*

*Network is a classful network address.

Every device on network uses the same subnet mask

network 172.16.0.0

network 192.168.10.0

router IGRP 10network 172.16.0.0

network 10.0.0.0

router IGRP 10

172.16.10.0 192.168.10.010.3.5.0

Configuring IGRP


Verifying IGRP

Router# show ip route

Router# show ip protocols

Router# debug ip igrp transaction

Router# debug ip igrp events

Router# undebug all (un all)

sypcnsa department2007 summer youth program: internal protocols: rip & igrp

Documents

ip classless slide

host b slide

destination ip address

routed slide

bgp routing protocols

routing information

unidirectional slide

b stub network