:05: %ISDN-6-CONNECT: Interface BRI1/0:1 is now connected to 7801000 Chicago Changing the sent hostname. Sometimes, the hostname of the calling router cannot be used for CHAP authentication. A common example is when you connect your router to an ISP. Figure 26-2 shows another simple two-router network: in this case, BobsRouter is connecting to a router named ISP. The service provider controlling the ISP router issues usernames and passwords to its clients. These usernames do not match the hostnames of the client's routers. Basic (Non-AAA) Authentication Calling Called BRI 1/0 BRI 1/0 BobsRouter Figure 26-2. CHAP authentication with configured username Bob, the client who is using BobsRouter, has been given the username Bob-01 and the password SuperSecret1. On the calling side, I've configured the additional command ppp chap hostname. This has the effect of using the name Bob-01 instead of the router's hostname for authentication. Notice that the username Bob-01 appears on the called side and that there is no reference on the called side to the hostname of the calling side: Calling side: Hostname BobsRouter username ISP password 0 SuperSecret1 interface BRI1/0 encapsulation ppp ppp authentication chap callin ppp chap hostname Bob-01 Called side: Hostname ISP username Bob-01 password 0 SuperSecret1 interface BRI1/0 encapsulation ppp ppp authentication chap While this configuration works, chances are the only place you'd see it is on a certifi- cation exam. A far more logical approach is to configure the sent username and pass- word in CHAP without having to configure a username that matches the hostname of the remote router: Calling side: Hostname BobsRouter interface BRI1/0 encapsulation ppp ppp authentication chap callin ppp chap hostname Bob-01 ppp chap password 0 SuperSecret1 Called side: Chapter 26: Authentication in Cisco Devices Hostname ISP username Bob-01 password 0 SuperSecret1 interface BRI1/0 encapsulation ppp ppp authentication chap With this method, there is no confusion resulting from trying to match