RADIUS security servers identification:
â€¢Host IP address
â€¢Host name and specific UDP port numbers
â€¢IP address and specific UDP port numbers
The combination of the IP address and UDP port number creates a unique identifier, that enables RADIUS requests to be sent to multiple UDP ports on a server at the same IP address. If two different host entries on the same RADIUS server are configured for the same service (for example, authentication) the second host entry that is configured functions as the failover backup to the first one. The RADIUS host entries are chosen in the order that they were configured.
how to configure the RADIUS server parameters on a switch:
Switch(config)# ip radius source-interface Vlan80 Switch(config)# radius-server host 172.l20.39.46 test username user1 Switch(config)# radius-server key rad123 Switch(config)# radius-server dead-criteria tries 2