RIPv2

Routing Information Protocol Version 2

The first classless routing protocol is the evolution of RIP v1, plus it supports VLSM (Variable Length Subnet Mask).

RIPv2 is known as a Vector Distance protocol and uses the following features to avoid routing loops:

• Split Horizon: prevents advertising routes learned on interface A to the same interface (A). For example, 1.1.1.0/24 learned on g1/3 can be advertised to other router interfaces but not on interface g1/3.
  
• Route Poisoning: ensures that all routers are aware of a failed route. It is implemented by advertising the failed route with an infinite metric.

Syntax:

router(config)#router rip
router(config-router)#version 2
router(config-router)#network a.a.a.a
router(config-router)#network b.b.b.b
router(config-router)#network c.c.c.c

Where:

• router rip.- Command to access the router configuration mode assigning the RIP routing protocol.
• version 2.- Command that indicates the version of the RIP protocol.
• network.- Command is used for the router to publish the networks in its RIP update packets.
• a.a.a.a – Network to be published by the router.

RIPv2 performs auto-summarization by default; with the following command, we can disable it:

router(config-router)#no auto-summary

In RIPv2, you can configure passive interfaces to stop sending RIP updates to other routers.

(config-router)#passive-interface default|g0/1

In RIPv2, a default route can be advertised with the following command:

R1(config-router)# default-information originate

Validation commands:

show ip route rip
show ip protocols
show ip rip database