1 © 2003, Cisco Systems, Inc. All rights reserved. CCNP 1 v3.0 Module 4 Routing Information Protocol version 2

222 © 2003, Cisco Systems, Inc. All rights reserved. Objectives RIP v2 Overview Configuring RIP v2 Verifying RIP v2 Operation

333 © 2003, Cisco Systems, Inc. All rights reserved. RIP v2 Operation

444 © 2003, Cisco Systems, Inc. All rights reserved. Issues Addressed by RIP v2 Authentication Addition of subnet masks and VLSM Next hop IP addressed Multicasting RIP v2 routing updates

555 © 2003, Cisco Systems, Inc. All rights reserved. RIP v2 Message Format

666 © 2003, Cisco Systems, Inc. All rights reserved. Compatibility with RIP v1 RFC 1723 defines a compatibility switch with four settings, which allows versions 1 and 2 to interoperate: RIP v1, in which only RIP v1 messages are transmitted. RIP v1 Compatibility, which causes RIP v2 to broadcast its messages instead of multicast them so that RIP v1 may receive them. RIP v2, in which RIP v2 messages are multicast to destination address None, in which no updates are sent.

777 © 2003, Cisco Systems, Inc. All rights reserved. Classless Route Lookups Classless routing protocols allow us to summarize these routes

888 © 2003, Cisco Systems, Inc. All rights reserved. Classless Routing Protocols

999 © 2003, Cisco Systems, Inc. All rights reserved. RIP v2 Authentication

10 © 2003, Cisco Systems, Inc. All rights reserved. Limitations of RIP v2 The more significant limitations that were inherited by RIP v2 include the following: Lack of alternative routes Counting to infinity 15-hop maximum Static distance vector metrics

11 © 2003, Cisco Systems, Inc. All rights reserved. Basic RIP v2 Configuration

12 © 2003, Cisco Systems, Inc. All rights reserved. Discontiguous Subnets and Classless Routing The same rules of discontiguous subnets applies to RIPv2 as we have discussed with EIGRP. Use the ‘no auto-summary’ command when you have discontiguous subnets.

13 © 2003, Cisco Systems, Inc. All rights reserved. Configuring Authentication The steps for setting up RIP v2 authentication are as follows: 1.Define a key chain with a name. 2.Define the key or keys on the key chain. 3.Enable authentication on an interface and specify the key chain to be used. 4.Specify whether the interface will use clear text or MD5 authentication. 5.Optionally configure key management.

14 © 2003, Cisco Systems, Inc. All rights reserved. Configuration tasks for RIP Authentication Vista(config)#key chain PRIVATE Vista(config-keychain)#key 1 Vista(config-keychain-key)#key-string Vista(config)#interface serial 0/0 Vista(config-if)#ip rip authentication key-chain PRIVATE Vista(config-if)#ip rip authentication mode md5 The matching configuration would then have to be done on the next directly connected router.

15 © 2003, Cisco Systems, Inc. All rights reserved. Verifying RIP v2 Operation: show ip protocols command

16 © 2003, Cisco Systems, Inc. All rights reserved. Verifying RIP v2 Operation: show ip route command

17 © 2003, Cisco Systems, Inc. All rights reserved. Debug Commands Two configuration problems common to RIP v2 mismatched versions improperly configured authentication Use the debug ip rip EXEC command to display information on RIP routing transactions Router#debug ip rip [events] Use the debug ip routing EXEC command to display information on RIP routing table updates and route-cache updates Router#debug ip routing