Configuring Split Horizon - Cisco Catalyst 9500 series Configuration Manual

Configuring IP Unicast Routing
Step 8
Step 9

Configuring Split Horizon

Routers connected to broadcast-type IP networks and using distance-vector routing protocols normally use
the split-horizon mechanism to reduce the possibility of routing loops. Split horizon blocks information about
routes from being advertised by a router on any interface from which that information originated. This feature
can optimize communication among multiple routers, especially when links are broken.
In general, we do not recommend disabling split horizon unless you are certain that your application
Note
requires it to properly advertise routes.
Procedure
Step 1
Step 2
Command or Action
show ip interface interface-id
Example:
Device# show ip interface gigabitethernet
1/0/1
copy running-config startup-config
Example:
Device# copy running-config startup-config
Command or Action
enable
Example:
Device> enable
configure terminal
Example:
Device# configure terminal
Routing Configuration Guide, Cisco IOS XE Everest 16.6.x (Catalyst 9500 Switches)
Configuring Split Horizon
Purpose
Verifies your entries.
(Optional) Saves your entries in the
configuration file.
Purpose
Enables privileged EXEC mode. Enter your
password if prompted.
Enters the global configuration mode.
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