Configuring RIP-2 Route Summarization

Context

A large RIP network requires significant device memory to maintain large RIP routing tables. Transmitting and processing routing information requires large amounts of network resources. Route summarization can reduce the routing table size and minimize impact of route flapping on a network.

RIP-2 supports automatic summarization and manual summarization. Manual summarization takes precedence over automatic summarization. To advertise all subnet routes, disable automatic route summarization.

By default, if split horizon or poison reverse has been configured, classful route summarization becomes invalid. When summarized routes are sent to the natural network segment border, split horizon or poison reverse must be disabled.

Procedure

Configure RIP-2 automatic route summarization.
1. Run the system-view command to enter the system view.
2. Run the rip [ process-id ] command to enter the RIP view.
3. Run the version 2 command to set the RIP version to RIP-2.
4. Run the summary command to enable RIP-2 automatic route summarization.
5. (Optional) Run the summary always command to enable RIP-2 automatic route summarization regardless of whether split horizon and poison reverse are enabled.
  
  The summary command is used in the RIP view to enable RIP-2 classful network-based route summarization.
Configure RIP-2 manual route summarization.
1. Run the system-view command to enter the system view.
2. Run the interface interface-type interface-number command to enter the interface view.
3. (Optional) On an Ethernet interface, run undo portswitch
  The interface is switched to Layer 3 mode.
  
  By default, an Ethernet interface works in Layer 2 mode.
  
  Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support switching between Layer 2 and Layer 3 modes.
4. Run the rip summary-address ip-address mask [ avoid-feedback ] command to configure RIP-2 to advertise the summarized local IP address.
  
  The rip summary-address ip-address mask [ avoid-feedback ] command is used in the interface view to enable RIP-2 classless network-based route summarization.