22-29
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-03
Chapter22 Configuring IP Unicast Routing Configuring RIP
Note In general, disabling split horizon is not recommended unless you are certain that your application
requires it to properly advertise routes.
If you want to configure an interface running RIP to advertise a summarized lo cal IP ad dr ess po ol on a
network access server for dial-up clients, use the ip summary-address rip interface configuration
command.
Note If split horizon is enabled, neither autosummary nor interface IP summa ry addresses are advertised.
Beginning in privileged EXEC mode, follow these steps to set an interface to advertise a summarized
local IP address and to disable split horizon on the interface:
To disable IP summarization, use the no ip summary-address rip router configuration command.
In this example, the major net is 10.0.0.0. T he s u mm ary ad dre ss 1 0 .2.0 .0 ov er ri des th e au to sum ma ry
address of 10.0.0.0 so that 10.2.0.0 is advertised out interface Gigabit Ethern et 0.2, an d 10.0.0 .0 is not
advertised. In the example, if the interface is still in Layer 2 mode (the default), you must enter a no
switchport interface configuration command before entering the ip address interface configuration
command.
Note If split horizon is enabled, neither autosummary nor interface summary addresses (those conf igured
with the ip summary-address rip router configuration command) are advertised.
Switch(config)# router rip
Switch(config-router)# interface gi0/2
Switch(config-if)# ip address 10.1.5.1 255.255.255.0
Switch(config-if)# ip summary-address rip 10.2.0.0 255.255.0.0
Switch(config-if)# no ip split-horizon
Switch(config-if)# exit
Switch(config)# router rip
Switch(config-router)# network 10.0.0.0
Switch(config-router)# neighbor 2.2.2.2 peer-group mygroup
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface interface-id Enter interface configuration mode, and speci fy the L ayer 3
interface to configure.
Step3 ip address ip-address subnet-mask Configure the IP address and IP subnet.
Step4 ip summary-address rip ip address ip-network mask Configure the IP address to be summarized and the IP
network mask.
Step5 no ip split horizon Disable split horizon on the interface.
Step6 end Return to privileged EXEC mode.
Step7 show ip interface interface-id Verify your entries.
Step8 copy running-config startup-config (Optional) Save your entries in the configuration file.