Command
PPP CHAP Hostname
Use
This command is used to send a hostname to a remote CHAP server for authentication.
Syntax
Router(config-if)#ppp chap hostname <hostname>
Example
In this example R1’s S1/1 interface is configured to authenticate R3 using CHAP.
R1(config)#int s1/1 R1(config-if)#encapsulation ppp R1(config-if)#ppp authentication chap R1(config-if)# *Mar 2 01:42:38.237: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1/1, changed state to down R1(config-if)#exit R1(config)#username R3 password cisco
Here R3 sends its hostname and password to be authenticated by R1
R3(config-if)#int s1/1 R3(config-if)#encapsulation ppp R3(config-if)#ppp chap hostname R3 R3(config-if)#ppp chap password cisco R3(config-if)# *Mar 2 01:43:43.697: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1/1, changed state to up
Below is the debug output for the CHAP authentication.
R3(config-if)#do debug ppp authe PPP authentication debugging is on R3(config-if)# *Mar 2 02:32:21.521: %LINK-5-CHANGED: Interface Serial1/1, changed state to administratively down *Mar 2 02:32:22.593: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1/1, changed state to down R3(config-if)#no shut R3(config-if)# *Mar 2 02:32:30.001: %LINK-3-UPDOWN: Interface Serial1/1, changed state to up R3(config-if)# *Mar 2 02:32:30.009: Se1/1 PPP: Using default call direction *Mar 2 02:32:30.013: Se1/1 PPP: Treating connection as a dedicated line *Mar 2 02:32:30.013: Se1/1 PPP: Session handle[FF00001B] Session id[28] *Mar 2 02:32:30.017: Se1/1 PPP: Authorization required *Mar 2 02:32:30.101: Se1/1 PPP: No authorization without authentication *Mar 2 02:32:30.125: Se1/1 CHAP: I CHALLENGE id 27 len 23 from “R1” *Mar 2 02:32:30.141: Se1/1 CHAP: Using hostname from interface CHAP *Mar 2 02:32:30.141: Se1/1 CHAP: Using password from interface CHAP *Mar 2 02:32:30.145: Se1/1 CHAP: O RESPONSE id 27 len 23 from “R3” *Mar 2 02:32:30.161: Se1/1 CHAP: I SUCCESS id 27 len 4 R3(config-if)#