1. PCFresher.com
Error 691
You may receive error 691 when you attempt to log in to VPN servers. Basically this is an
authentication error as it is linked with the username and password. Here is error message
you receive on your screen
“Error 691: Access denied because username and password is invalid on the
domain”
Resolution Steps
· Verify Your Logon Credentials
· Access Resources on Network
· Browse through PPTP/VPN Connection
· Access Roaming Profiles
· Authenticate Remote Client
· Limit VPN User Login Time
Verify your logon credentials
To resolve VPN error 691 verify logon credentials. Follow these instructions:
1. Ensure that you have entered correct logon ID and password.
2. Right click on Dial-up connection, select Properties. Click the Options tab.
3. Unmark “Include Windows Logon Domain” checkbox.
4. Remove all .pwl files
5. If you are still having problems, create and use new login ID.
Access Resources on Network
Error 691 prevents you to access network resources. Follow these steps:
1. Contact your network admin to verify DNS and WINS settings.
2. Select Entire Network Option for LAN protocols for VPN Clients.

2. PCFresher.com
Browse through PPTP/VPN Connection
1. Enable NetBIOS on workgroup network.
2. Move WINS to another computer if PPTP/VPN and WINS are on same computer.
3. Set TCP port to 139 and UDP port to 137.
4. Check the client has correct WINS and DNS settings.
5. Use following command to access remote resources
net use h: serveripsharename
Access Roaming Profiles
Sometimes you are unable to access login scripts because of roaming profiles, policies
applied on home folders. In this situation, you need to perform following steps
1. Download latest Service Pack
2. Use hybrid mode to access roaming profiles (use regedit to change your mode)
Authenticate Remote Client
You may not access roaming profiles after downloading latest service pack for Win 2000. In
this situation you have to authenticate remote client to DC. Performing following
troubleshooting steps
1. Get login credentials and setup site to VPN
2. Mark “Logon using Dial-up Connection”.
Limit VPN user login time
You need to limit VPN user login time in order to rectify VPN error 691. Follow these
troubleshooting steps:
1. Setup logon hours after getting domain control. You can do that under AD Users and
Computers.
2. To setup access time you need to use Remote Access Policy.
3. Restrict logon hours through net user command.