R2(config-if)#ppp authentication ?
chap Challenge Handshake Authentication Protocol (CHAP)
eap Extensible Authentication Protocol (EAP)
ms-chap Microsoft Challenge Handshake Authentication Protocol (MS-CHAP)
ms-chap-v2 Microsoft CHAP Version 2 (MS-CHAP-V2)
pap Password Authentication Protocol (PAP)
Doesn't look like there is an Md5 option...or is there? I looked up the ppp authentication commands in the DocCD:
-12.4 Mainline
-Master Index
-Cisco IOS Master Command List, All Releases
-ppp authentication MWP-147, SEC-1481
Click the SEC-1481 link
Now is where I used the browser search to look for "Md5." Not sure if this is possible in the lab so you may have to quickly scan with your eyes. The only hit comes up under "ppp eap local" command. You will see this phrase:
"In local mode, the EAP session is authenticated using the MD5 algorithm and obeys the same authentication rules as does Challenge Handshake Authentication Protocol (CHAP)."
Voila!
So now that we know what mode we need everything else is easy, and it works just like CHAP. On both sides:
username R5 password cisco
interface Serial1/1
ip address 150.100.25.2 255.255.255.0
encapsulation ppp
ppp authentication eap
ppp eap password 0 cisco
ppp eap local
Always verify just to make sure it's working:
R2#debug ppp authentication
