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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 22 Configuring IP Unicast Routing
Configuring RIP
RIP Authentication
RIP version 1 does not support authentication. If you are sending and receiving RIP Version 2 packets,
you can enable RIP authentication on an interface. The key chain determines the set of keys that can be
used on the interface. If a key chain is not configured, no authentication is performed, not even the
default. Therefore, you must also perform the tasks in the
“Managing Authentication Keys” section on
page 22-63
.
The switch supports two modes of authentication on interfaces for which RIP authentication is enabled:
plain text and MD5. The default is plain text.
Beginning in privileged EXEC mode, follow these steps to configure RIP authentication on an interface:
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.
This example shows how to verify the setting by using the show running-config interface privileged
EXEC command.
Switch# show running-config interface gigabitethernet0/3
Building configuration...
Current configuration : 158 bytes
!
interface GigabitEthernet0/3
no switchport
ip address 10.1.3.59 255.255.255.0
ip directed-broadcast
ip irdp
ip rip authentication key-chain CHAIN
end
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.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
interface interface-id
Enter interface configuration mode, and specify the
interface to configure.
Step 3
ip rip authentication key-chain name-of-chain
Enable RIP authentication.
Step 4
ip rip authentication mode [text | md5}
Configure the interface to use plain text authentication (the
default) or MD5 digest authentication.
Step 5
end
Return to privileged EXEC mode.
Step 6
show running-config interface [interface-id]
Verify your entries.
Step 7
copy running-config startup-config
(Optional) Save your entries in the configuration file.