aaa...

triple A

not the towing service

authentication- identification method, includes login, password, challenge and response, message support, and perhaps encryption

authorization- remote access control methodology, authorization per instance and/or authorization per service, per account, per profile and user group and protocol support (ip, telnet, etc)

accounting- the method of charging and collecting (funny money)

configuration

dls1(config)#aaa new-model

for tacacs and radius support

terminal access controller access control system (why, why, why)
remote authentication dial-in user service




    uh-huh


then... set up login parameters, point to the server, set up a server key and...

watch your mind melt as you read this:

http://www.cisco.com/en/US/tech/tk59/technologies_tech_note09186a0080093c81.shtml