Summary Addresses And Split Horizon - Cisco ONS 15454 SDH Configuration Manual

Configuring RIP
Beginning in privileged EXEC mode, follow this procedure to configure RIP authentication on an
interface:
Command
Step 1
Router# configure terminal
Step 2
Router(config)# interface interface-id
Step 3
Router(config-if)# ip rip
authentication key-chain name-of-chain
Step 4
Router(config-if)# ip rip
authentication mode {text | md5}
Step 5
Router(config-if)# end
Step 6
Router# show running-config interface
[ interface-id ]
Step 7
Router# copy running-config
startup-config
To restore clear text authentication, use the no ip rip authentication mode interface configuration
command. To prevent authentication, use the no ip rip authentication key-chain interface
configuration command.

Summary Addresses and 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 usually optimizes communication among multiple routers, especially when links
are broken.
In general, disabling split horizon is not recommended unless you are certain that your application
Note
requires it to properly advertise routes.
If you want to configure an interface running RIP to advertise a summarized local IP address pool on a
network access server for dial-up clients, use the ip summary-address rip interface configuration
command.
Beginning in privileged EXEC mode, follow these steps to set an interface to advertise a summarized
local IP address pool and to disable split horizon on the interface:
Command
Step 1
Router# configure terminal
Step 2
Router(config)# interface
interface-id
Step 3
Router(config-if)# ip address
ip-address subnet-mask
Cisco ONS 15454 and Cisco ONS 15454 SDH Ethernet Card Software Feature and Configuration Guide, R8.0
11-8
Chapter 11 Configuring Networking Protocols
Purpose
Enters global configuration mode.
Enters interface configuration mode, and specifies the
interface to configure.
Enables RIP authentication.
Configures the interface to use plain text
authentication (the default) or MD5 digest
authentication.
Returns to privileged EXEC mode.
Verifies your entries.
(Optional) Saves your entries in the configuration file.
Purpose
Enters global configuration mode.
Enters interface configuration mode, and specifies the
Layer 3 interface to configure.
Configures the IP address and IP subnet.