Administrator Guide

If you must perform routing between discontiguous subnets, disable automatic summarization. With automatic route summarization
disabled, subnets are advertised.
The autosummary command requires no other conguration commands. To disable automatic route summarization, enter no
autosummary in ROUTER RIP mode.
NOTE: If you enable the ip split-horizon command on an interface, the system does not advertise the summarized
address.
Controlling Route Metrics
As a distance-vector protocol, RIP uses hop counts to determine the best route, but sometimes the shortest hop count is a route
over the lowest-speed link.
To manipulate RIP routes so that the routing protocol prefers a dierent route, manipulate the route by using the offset command.
Exercise caution when applying an offset command to routers on a broadcast network, as the router using the offset command
is modifying RIP advertisements before sending out those advertisements.
The distance command also allows you to manipulate route metrics. To assign dierent weights to routes so that the ones with
the lower weight or administrative distance assigned are preferred, use the distance command.
To set route matrixes, use the following commands.
• Apply a weight to all routes or a specic route and ACL.
ROUTER RIP mode
distance weight [ip-address mask [access-list-name]]
Congure the following parameters:
– weight: the range is from 1 to 255. The default is 120.
– ip-address mask: the IP address in dotted decimal format (A.B.C.D), and the mask in slash format (/x).
– access-list-name: the name of a congured IP ACL.
• Apply an additional number to the incoming or outgoing route metrics.
ROUTER RIP mode
offset-list access-list-name {in | out} offset [interface]
Congure the following parameters:
– prefix-list-name: the name of an established Prex list to determine which incoming routes are modied
– offset: the range is from 0 to 16.
– interface: the type, slot, and number of an interface.
To view the conguration changes, use the show config command in ROUTER RIP mode.
Debugging RIP
The debug ip rip command enables RIP debugging.
When you enable debugging, you can view information on RIP protocol changes or RIP routes.
To enable RIP debugging, use the following command.
•
debug ip rip [interface | database | events | trigger]
EXEC privilege mode
Enable debugging of RIP.
Example of the debug ip rip Command
The following example shows the conrmation when you enable the debug function.
Routing Information Protocol (RIP)
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