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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 22 Configuring IP Unicast Routing
Configuring Protocol-Independent Features
To remove a distance definition, use the no distance router configuration command.
Managing Authentication Keys
Key management is a method of controlling authentication keys used by routing protocols. Not all
protocols can use key management. Authentication keys are available for EIGRP and RIP Version 2.
Before you manage authentication keys, you must enable authentication. See the appropriate protocol
section to see how to enable authentication for that protocol. To manage authentication keys, define a
key chain, identify the keys that belong to the key chain, and specify how long each key is valid. Each
key has its own key identifier (specified with the key number key chain configuration command), which
is stored locally. The combination of the key identifier and the interface associated with the message
uniquely identifies the authentication algorithm and Message Digest 5 (MD5) authentication key in use.
You can configure multiple keys with life times. Only one authentication packet is sent, regardless of
how many valid keys exist. The software examines the key numbers in order from lowest to highest, and
uses the first valid key it encounters. The lifetimes allow for overlap during key changes. Note that the
router must know these lifetimes.
Beginning in privileged EXEC mode, follow these steps to manage authentication keys:
Step 3
distance weight {ip-address {ip-address mask}}
[ip access list]
Define an administrative distance.
weight—The administrative distance as an integer from
10 to 255. Used alone, weight specifies a default
administrative distance that is used when no other
specification exists for a routing information source.
Routes with a distance of 255 are not installed in the
routing table.
(Optional) ip access list—An IP standard or extended
access list to be applied to incoming routing updates.
Step 4
end
Return to privileged EXEC mode.
Step 5
show ip protocols
Display the default administrative distance for a
specified routing process.
Step 6
copy running-config startup-config
(Optional) Save your entries in the configuration file.
Command
Purpose
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
key chain name-of-chain
Identify a key chain, and enter key chain configuration
mode.
Step 3
key number
Identify the key number. The range is 0 to 2147483647.
Step 4
key-string text
Identify the key string. The string can contain from 1 to
80 uppercase and lowercase alphanumeric characters,
but the first character cannot be a number.
