Media for Cisco 1720 12.3(16) CHAP Authen Problem

Cisco 1720 12.3(16) CHAP Authen Problem

Hello all!

I'm stumped on a CHAP Authen issue.

I have a Cisco 1720 w/ a external USR 56k Modem on the Aux port. The goal is to have the router connect into a Windows RAS server using CHAP authentication. Here is my current config:

chat-script Dialout ABORT ERROR ABORT BUSY "" "AT" OK "ATDT \T" TIMEOUT

45 CONNECT \c modemcap entry test:MSC=&F1E0Q0F1&C1&D2S0=0 ! interface Async5 no ip address encapsulation ppp no ip route-cache dialer in-band dialer pool-member 1 async dynamic routing no fair-queue ! interface Dialer1 ip address negotiated ip nat outside encapsulation ppp no ip route-cache dialer pool 1 dialer string 9,1877XXXXXXX modem-script Dialout dialer-group 1 no cdp enable ppp authentication chap ppp chap hostname XXXXXXX ppp chap password 0 XXXXXX ! dialer-list 1 protocol ip permit ! line aux 0 exec-timeout 0 0 script dialer Dialout modem InOut modem autoconfigure type test no exec transport input all stopbits 1 speed 115200 flowcontrol hardware !

When I atempt the connection, the modem dials and handshakes, but Authentication fails. When looking at debug ppp neg and debug ppp authen, I see the following:

*Mar 1 01:47:46.691: As5 CHAP: O CHALLENGE id 45 len 28 from "XXXXX" *Mar 1 01:47:46.895: As5 MS-CHAP-V2: I CHALLENGE id 0 len 33 from "XXXXXX" *Mar 1 01:47:46.931: As5 MS CHAP V2: Using hostname from interface CHAP *Mar 1 01:47:46.931: As5 MS CHAP V2: Using password from interface CHAP *Mar 1 01:47:46.931: As5 MS-CHAP-V2: O RESPONSE id 0 len 61 from "XXXXX" *Mar 1 01:47:47.135: As5 MS-CHAP-V2: I FAILURE id 0 len 52 msg is "E=691 R=1 C=8B41DD421538F205006FFB81E710A608 V=3"

On the Windows RAS side, I have also configured the user to authenticate using CHAP or PAP and explicitly disabled MS-CHAP-V2. I am not sure how the CPE decides to start trying to authenticate as MS-CHAP-V2.

On a side note, I have also attempted this into an Astra CVX box and have had the same results. The Astra does not even have the option to MS-CHAP-V2 in its configs.

Any help is appricated.