JSI Tip 1455. RRAS does not offer MS-CHAP authentication when used as a Radius Client.

We can force it, by using Regedt32 to navigate to:

HKEY_LOCAL_MACHINESystemCurrentControlSetServicesRasmanPPPCHAP

On the Edit menu, Add Value name OfferMSCHAP, a type REG_DWORD, and enter a 1 in the DWORD Editor.

Once this value is set, all incoming PPP connections will be offered MS-CHAP. MS-CHAP will be used to authenticate each PPP user against the Radius server that your RAS server uses.