PART 7: RIP Miscellaneous

Routing Information Protocol

RIP Neighbor Configuration

By default, RIPv2 sends updates to the multicast address 224.0.0.9. However, you can configure static neighbors for unicast communication:

Router(config-router)# neighbor x.x.x.x

Important considerations when using the neighbor command:

• This command does NOT stop multicast updates - it only adds unicast communication

• To stop multicast flooding completely, you must make the interface passive

• Useful for communicating with RIP neighbors across non-broadcast networks

• Can help reduce unnecessary update traffic in certain topologies

Example use case:

Router(config-router)# neighbor 10.1.2.2
Router(config-router)# passive-interface fa0/1

This configuration sends unicast updates only to 10.1.2.2 and stops multicast updates on the fa0/1 interface.

RIP Version Control

Cisco routers can only run a single RIP process, but that process can support both RIPv1 and RIPv2 simultaneously. There are multiple ways to control which RIP version is used:

1. Process-Level Configuration:

Router(config-router)# version {1|2}

2. Interface-Level Configuration:

Router(config-if)# ip rip send version {1|2|1 2}
Router(config-if)# ip rip receive version {1|2|1 2}

These commands provide granular control over which versions are sent or received on specific interfaces.

Version compatibility notes:

• RIPv1 and RIPv2 are backward compatible

• A router configured for both versions can process packets from either version

• You can configure different interfaces to use different versions

• When a router receives a packet of a different version than configured, it will still process it correctly

This flexibility allows for gradual migration from RIPv1 to RIPv2 across a network, or for maintaining compatibility with older devices that only support RIPv1.

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