Router(config)# hostname name
• Assigns a host name to your router
Router(config)# username name password password
• Identifies the username and password of remote router
To configure PPP authentication, the interface must be configured for PPP encapsulation. Enable PAP or CHAP authentication by performing the following steps:
Step 1 Verify that each router has a host name assigned to it. To assign a host name, enter the hostname name command in global configuration mode. This name must match the username expected by the authenticating router at the other end of the link.
Step 2 On each router, define the username and password to expect from the remote router with the username name password password global configuration command.
Add a username entry for each remote system that the local router communicates with and that requires authentication. Note that the remote device must have a corresponding username entry for the local router with a matching password.
Router(config-if)# ppp authentication {chap | chap pap | pap chap | pap}
Configure PPP authentication with the ppp authentication {chap | chap pap | pap chap | pap} interface configuration command.
If you configure ppp authentication chap on an interface, all incoming calls on that interface that initiate a PPP connection will be authenticated using CHAP. Likewise, if you configure ppp authentication pap, all incoming calls that start a PPP connection will be authenticated using PAP.
If you configure ppp authentication chap pap, the router will attempt to authenticate all incoming calls that start a PPP session by using CHAP. If the remote device does not support CHAP, the router will try to authenticate the call by using PAP. If the remote device does not support either CHAP or PAP, authentication will fail and the call will be dropped.
If you configure ppp authentication pap chap, the router will attempt to authenticate all incoming calls that start a PPP session with PAP. If the remote device does not support PAP, the access server will try to authenticate the call using CHAP. If the remote device does not support either protocol, authentication will fail and the call will be dropped.
Note If both methods are enabled, the first method that is specified will be requested during link negotiation. If the peer suggests using the second method or simply refuses the first method, the second method will be tried.