VPN Error Code: 732, 734, 812
732: Your computer and the remote computer could not agree on PPP control protocols.
734: The PPP link control protocol was terminated.
812: The connection was prevented because of a policy configured on your RAS/VPN server. Specifically, the authentication method used by the server to verify your username and password may not match the authentication method configured in your connection profile. Please contact the Administrator of the RAS server and notify them of this error.
Possible Causes: One of the prime causes for the above error is: when the *only* allowed authentication protocol configured on VPN server (or Radius server) is MS-CHAP and the VPN client is Vista or above OS platform (like Windows7). Note: due to security reasons MS-CHAP was removed from Vista and above OS platform and hence the connection fails.
Error 812 comes when Authentication protocol is set via NPS (Network Policy and Access Services) otherwise Error 732/734.
Event log 20276 is logged to the event viewer when RRAS based VPN server authentication protocol setting mismatches which that of the VPN client machine.
Possible Solution: Configure a more secured authentication protocol like MS-CHAPv2 or EAP based authentication on the server – which matches the settings on the client side.