VPN error 691 is one of the most common problems that VPN users worry about in Windows 10. The error message appears when connecting to the VPN and users cannot access the internet through the VPN.
There are various reasons that can cause error 691 on your PC. When the VPN cannot confirm the authenticity of the connection, you will get this error. You will also get this error if you are using the wrong user ID or password to log into the VPN. Using a public VPN domain or an incorrect or disallowed domain could also cause this problem. Sometimes this error can also cause problems if the network security settings are incorrect.
Whatever the problem is, here we take a look at some of the solutions that have been tried and tested by various users to fix the VPN error 691 in Windows 10.
Solution 1: Make sure you are using the correct login ID and password
One of the main reasons you might be getting error 691 on your VPN could be an incorrect login ID or password. Make sure you are using the correct user ID and typing the password correctly. Before logging into VPN, use the See password option to see if the password is correct. It could also be possible that the Caps Lock file is enabled, causing the wrong password to be entered.
If you are not sure if you entered the correct password, go ahead, reset your password and log in again.
If the error persists, try the next solution.
Solution 2: Remove the .local extension from the domain name
When you log into the VPN, in addition to entering your username and password, you also get a field to enter the domain name. Here you can try to remove .Locale extension if added with domain name. After removing the .local extension, try to log in to the VPN. If that doesn't fix the problem, try the next solution.
Solution 3: Keep the domain name blank during VPN access
If the above solution of removing the .Locale suffix file didn't work, here's another thing you can try. Go ahead and clear the Domain Name field from the VPN login screen and log in with your user ID and password only. Were you able to log into the VPN without receiving error 691?
Solution 4: Enable Microsoft CHAP version 2
Enabling Microsoft CHAP version 2 in the properties of the VPN connection can help you get rid of this problem. Here's how to do it:
Step 1: Open the Windows menu by pressing the key Win + X keys. From the menu, select the file Network connection option.
Step 2: A new window will open with the list of connections on your PC. Here, identify and right-click on the VPN connection, then in the menu that opens, select the file Property option.
3 pass: When the Properties window appears, navigate to the file Safety language. Here, make sure the Allow these protocols option is selected, then select the file Microsoft CHAP version 2 (MS-CHAP v2). Please select ok to save the settings.
Once you've saved your settings, check that the VPN error 691 is still worrying you.
Solution 5: disable the "Include Windows logon domain" option
Another change you can make to your VPN settings to resolve the error 691 issue is to disable the Include Windows logon domain option. Let's review the steps:
Step 1: Select the Network connections option of Win + X menu.
Step 2: Right click on the VPN in the new window and select the file Property option.
3 pass: Go to Choices language. There under the Composition options section, deselect the file Include the Windows logon domain option.
Now click ok to save the settings. Exit the VPN properties window and check if the VPN problem is resolved.
Solution 6: Change LAN Manager parameters
With the Group Policy Editor in Windows, you can make a couple of changes to the LAN Manager parameters. This method worked for several users who encountered VPN error 691 on Windows 10.
Step 1: Opens the Group Policy Editor. For this, press the button Win + R keys, then in the Run box, type gpedit.msc and press the button Log in key.
Step 2: The Group Policy Editor will open. Here, go to the left panel and go to the location mentioned below, then go to the right panel and double click Network Security - LAN Manager authentication level option:
Computer Configuration > Windows Settings > Security Settings > Local Policies > Security Options
3 pass: A properties window will open. Here, click on the drop-down menu and select the file Submit LM and NTLM responses option. Click on ok per salvare I modified it.
4 passNow go back to the Group Policy Editor and double click on the file Network Security: Minimum session security for NTLM SSP option available in the right pane.
5 pass: A new Properties window will open. Here, uncheck the file Requires 128-bit encryption e seleziona l'opzione Request NTLMv2 session security option. Click on ok to save the settings.
Once the changes are made, restart your PC and see if the 691 error is resolved.
Solution 8: update the network driver
If the network device driver on your PC is out of date, you may face a number of issues, including VPN issues. You will need to make sure the network driver is up to date. See the steps below:
Step 1: Press Win + X keys on the keyboard. From the menu, select the file Device administrator option.
Step 2: In the Device Manager window, expand the file Network adapters device, then right-click the Wi-Fi receiver driver and select the file Update the driver software option.
3 pass: Now a new window will open. Here, select the file Automatically searches for updated driver software option. Now your PC will start looking for the updated version of the network driver you are trying to update. If a newer version of the driver is found, you will be prompted for the same.
Follow the onscreen instructions to complete the update process. To apply the driver update settings correctly, restart your PC. After restarting your PC, you will be able to access the internet via VPN.
Solution 9: Use the resphone command for your VPN connection
Another method that has worked for many users to fix the VPN error 691 in Windows 10 is the to call again I'm sending. You need to run this command from the command prompt with administrator privileges. Follow the steps below:
Step 1: Press Win + X keys. The Windows menu will open; here select the file Command Prompt (Admin) option.
Step 2: In the Command Prompt window that will open, type the following command and press the key Log in key:
rasphone -d VPNname
Now in the above command, replace the VPN name with the name of the VPN connection on your PC. You can open the file Network connections from Win + X and find the name of the VPN connection.
Once the command is successful, go ahead and check if the VPN problem is resolved.
Solution 10: Check for another active VPN connection
This solution is for those users who use more than 1 VPN on their PC. One of the VPNs may already be running on your PC. When you try to run another VPN on top of the other, you may get this error on your PC.
Make sure only one VPN is active at a time. If you don't remember turning on any VPN after turning on your PC, one of the VPNs may be able to start by itself. If so, perform a clean boot on your PC. This way you will make sure that only essential Windows services are started when you turn on your PC. Try connecting to the VPN now and see if you get the same error.
Solution: 11 Re-register the VPN connection
Windows 10 comes loaded with a built-in VPN. If you are using the Windows VPN service, you may want to remove the VPN connection you are using and re-add it in settings. Let's see how to do it:
Step 1: Open the settings application on your PC. For this, press the button Win + me buttons.
Step 2: In the Settings app, select the file Network and internet option.
3 pass: When the new window opens, go to the left panel and select the file VPN option. Now go to the right panel and select the VPN connection. From the options that will appear, select the file To remove button.
4 pass: After the VPN connection is removed, select the file Add a VPN connection option. In the next window, fill in all required fields needed to add the VPN connection again.
After re-registering the VPN connection on your PC, check if the problem is resolved or not. You can also try restarting your PC before trying the new VPN connection.
While the above solutions are enough to fix the VPN error 691 in Windows 10, if you still can't fix the problem, let us know in the comments and we'll get back to you. We would also be very grateful if you would let us know which of the solutions worked for you.