Setting Authentication for routing updates

Authentication in receiving and processing a routing update is important. In this way, the received information is trusted before it is being processed. The authentication method can be done in two ways which is clear text, and MD5. When using clear text, the password that has been set can be clearly seen. When using MD5, the password is encrypted. Therefore, it is recommended to use MD5 authentication.

To set the password in routing updates:
(config)#key chain //word is used to remember the key
(config-keychain)#key //set a key number to be configured later
(config-keychain-key)#key-string //set the password for the key number

Then apply the key to an interface:
(config)# // apply the key to an interface
(config-if)#ip rip authentication mode // choose MD5 or text
(config-if)#ip rip authentication key-chain //the must be the same as the in key chain configuration, not the password

Apply the same commands above (6 commands) to the peer of the interface communicating, including the same authentication mode (md5 or text), else communication will not happen since one of the router asks for authentication and the peer will not give the password since it does not know the password. Therefore, the router will ignore packets from other router since the password is not the same (invalid authentication).

-- 22 December 2010 --