1 © 2003, Cisco Systems, Inc. All rights reserved.

CCNA 2 Module 7 Distance Vector Routing

Protocols

2 2 2 © 2003, Cisco Systems, Inc. All rights reserved.

Purpose of This PowerPoint

• This PowerPoint primarily consists of the Target Indicators (TIs) of this module in CCNA version 3.0.

• It was created to give instructors a PowerPoint to take and modify as their own.

• This PowerPoint is:

NOT a study guide for the module final assessment.

NOT a study guide for the CCNA certification exam.

• Please report any mistakes you find in this PowerPoint by using the Academy Connection Help link.

3 3 3 © 2003, Cisco Systems, Inc. All rights reserved.

To Locate Instructional Resource Materials on Academy Connection:

• Go to the Community FTP Center to locate materials created by the instructor community

• Go to the Tools section

• Go to the Alpha Preview section

• Go to the Community link under Resources

• See the resources available on the Class home page for classes you are offering

• Search http://www.cisco.com

• Contact your parent academy!

4 4 4 © 2003, Cisco Systems, Inc. All rights reserved.

Objectives

• Distance vector routing

• RIP

• IGRP

5 5 5 © 2003, Cisco Systems, Inc. All rights reserved.

Distance Vector Updates

6 6 6 © 2003, Cisco Systems, Inc. All rights reserved.

Problem: Routing Loops

• Routing loops can occur when inconsistent routing tables are not updated due to slow convergence in a changing network.

7 7 7 © 2003, Cisco Systems, Inc. All rights reserved.

Problem: Counting to Infinity

8 8 8 © 2003, Cisco Systems, Inc. All rights reserved.

Solution: Defining a Maximum for Infinity

9 9 9 © 2003, Cisco Systems, Inc. All rights reserved.

Solution: Split Horizon

10 10 10 © 2003, Cisco Systems, Inc. All rights reserved.

Solution: Route Poisoning

11 11 11 © 2003, Cisco Systems, Inc. All rights reserved.

Solution: Triggered Updates

12 12 12 © 2003, Cisco Systems, Inc. All rights reserved.

Solution: Holddown Timers

13 13 13 © 2003, Cisco Systems, Inc. All rights reserved.

Key Characteristics of RIP

14 14 14 © 2003, Cisco Systems, Inc. All rights reserved.

RIP Commands

• Using router rip and network

commands to Enable RIP

• Enabling RIP on an IP-addressed network

• Monitoring IP packet flow using the show ip protocol command

• The show ip route command

15 15 15 © 2003, Cisco Systems, Inc. All rights reserved.

Configuring RIP

16 16 16 © 2003, Cisco Systems, Inc. All rights reserved.

Using the ip classless Command

17 17 17 © 2003, Cisco Systems, Inc. All rights reserved.

RIP Configuration Issues

• To reduce routing loops and counting to infinity, RIP uses the following:

Defining infinity

Split horizon

Route poisoning & poison reverse

Triggered updates

Holddown timers

18 18 18 © 2003, Cisco Systems, Inc. All rights reserved.

The show ip protocols Command

19 19 19 © 2003, Cisco Systems, Inc. All rights reserved.

The show ip route Command

20 20 20 © 2003, Cisco Systems, Inc. All rights reserved.

Troubleshooting RIP Update Issues

• debug ip rip

• show ip rip database

• show ip protocols {summary}

• show ip route

• debug ip rip {events}

• show ip interface brief

21 21 21 © 2003, Cisco Systems, Inc. All rights reserved.

Preventing Routing Updates through an Interface

22 22 22 © 2003, Cisco Systems, Inc. All rights reserved.

Load Balancing with RIP

23 23 23 © 2003, Cisco Systems, Inc. All rights reserved.

Administrative Distance

24 24 24 © 2003, Cisco Systems, Inc. All rights reserved.

Integrating Static Route with RIP

• A router running RIP can receive a default route via an update from another router running RIP.

• Another option is for the router to generate the default route itself.

• The administrator can override a static route with dynamic routing information by adjusting the administrative distance values.

25 25 25 © 2003, Cisco Systems, Inc. All rights reserved.

IGRP Features

26 26 26 © 2003, Cisco Systems, Inc. All rights reserved.

IGRP Commands

• Using router igrp and network commands to enable IGRP

• Enabling IGRP on an IP-addressed network

• Monitoring IP packet flow using the show ip protocol command

• The show ip interfaces command

• The show ip route command

• The debug ip rip command

27 27 27 © 2003, Cisco Systems, Inc. All rights reserved.

IGRP Metrics

• Bandwidth – The lowest bandwidth value in the path

• Delay – The cumulative interface delay along the path

• Reliability – The reliability on the link towards the destination as determined by the exchange of keepalives

• Load – The load on a link towards the destination based on bits per second

28 28 28 © 2003, Cisco Systems, Inc. All rights reserved.

IGRP Routes: Interior, System, & Exterior

29 29 29 © 2003, Cisco Systems, Inc. All rights reserved.

IGRP Stability Features

• Holddowns, Split horizons, & Poison-reverse updates

30 30 30 © 2003, Cisco Systems, Inc. All rights reserved.

Configuring IGRP

31 31 31 © 2003, Cisco Systems, Inc. All rights reserved.

Migrating RIP to IGRP

1. Verify existing routing protocol (RIP) on the routers to be converted.

2. Configure IGRP on RouterA and RouterB

3. Enter show ip protocols on RouterA and RouterB

4. Enter show ip route on RouterA and RouterB

32 32 32 © 2003, Cisco Systems, Inc. All rights reserved.

Verifying IGRP Configuration

• Some commands for checking IGRP configuration are as follows:

show interface interface

show running-config

show running-config interface interface

show running-config | begin interface interface

show running-config | begin igrp

show ip protocols

33 33 33 © 2003, Cisco Systems, Inc. All rights reserved.

Troubleshooting IGRP

• The following commands are useful when troubleshooting IGRP:

show ip protocols {summary}

show ip route

debug ip igrp events IGRP protocol events

debug ip igrp transactions IGRP protocol transactions

ping

traceroute