 the group you'd like to create: aaa group server tacacs+ Login-Servers server 10.100.1.100 server 10.100.1.101 aaa group server radius PPP-Radius server 10.100.200.200 auth-port 1645 acct-port 1646 server 10.100.200.201 auth-port 1645 acct-port 1646 Again, with RADIUS, the router adds the port numbers. The commands entered were simply: R1(config)# aaa group server radius PPP-Radius R1(config-sg-radius)# server 10.100.200.200 21(config-sg-radius)# server 10.100.200.201 If you have a TACACS+ server that requires key authentication, you can add the key to an individual server within a group by using the server-private command instead of the server command: aaa group server tacacs+ Login-Servers server-private 10.100.1.72 key Secret Creating Method Lists A method list is a list of authentication methods to be used in order of preference. For example, you may want to first try TACACS+ and then, if that fails, use local user authentication. Once you've created a method list, you can then configure an inter- face to call the method list for authentication. A router can authenticate a user in a few different ways. They are: Login Login authentication is the means whereby a user is challenged to access the router's CLI. PPP authentication provides authentication for Point-to-Point Protocol connec- tivity either on serial links, or through something like modem connectivity. Chapter 24: Authentication in Cisco Devices AppleTalk Remote Access Protocol is a remote access protocol for AppleTalk users. NetWare Asynchronous Services Interface is a remote access protocol for Novell Netware users. In practice, you're only likely to encounter login and PPP authentication. With the advent of broadband Internet access in most homes, and the adoption of VPN at most companies, modem connectivity is becoming a thing of the past in most metro- politan areas. I haven't seen ARAP or NASI in the field in years, SO I'll only cover login and PPP authentication here. Login authentication When logging into a network device, you can be challeng