Configuring RIP-2 Route Summarization

Configuring RIP-2 route summarization reduces the routing table size, which improves system performance and network security.

Context

On a medium-or large-sized network, the routing table contains a large number of routes. Storing and managing the routes consume a large number of memory resources. To resolve this problem, RIP-2 provides the route summarization function. Route summarization allows multiple routes with the same IP prefix and destination IP address to be summarized into one, which reduces the number of routes in the routing table and minimizes system resource consumption. In addition, if a specific link frequently alternates between Up and Down, the links not involved in the route summarization will not be affected, which prevents route flapping and improves network stability.

RIP-1 does not support route summarization.

Procedure

Enable RIP-2 automatic route summarization.
1. Run system-view
  The system view is displayed.
2. Run rip [ process-id ]
  A RIP process is created, and the RIP view is displayed.
3. Run summary [ always ]
  RIP-2 automatic route summarization is enabled.
  
  If you specify always, RIP-2 automatic route summarization takes effect, regardless of whether split horizon and poison reverse has been configured.
4. Run commit
  The configuration is committed.
Configure RIP-2 to advertise the summarized route.
1. Run system-view
  The system view is displayed.
2. Run interface interface-type interface-number
  The interface view is displayed.
3. Run rip summary-address ip-address mask [ avoid-feedback ]
  RIP-2 is configured to advertise the summarized route to the specified IP address.
  
  If you specify avoid-feedback, the local interface does not learn the summarized route whose destination address is the same as that the advertised summarized route, which prevents routing loops.
4. Run commit
  The configuration is committed.