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17 Easy Fixes for VPN Error 691 in Windows 10/11
Error 691 is often the result of incorrect username or password
8 min. read
Updated onOctober 4, 2023
updated onOctober 4, 2023
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Key notes
Many useVPNsin order to protect their privacy online.VPNtools are a great thing to have these days, and Windows 10 also supportsVPNnatively, so you won’t need any third-party software.
Issues withVPNcan still occur andusersreportedConnectionfailedwith error 691error message. This can be a problem if you want to use aVPN, but there are a few ways to solve it.
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How to fix the VPN connection failed with error 691?
1. Install Private Internet Access
While the native Windows solution is fairly easy to use and covers basic VPN needs, if you rely extensively on VPN usage you might want to consider upgrading to premium software.
By coupling your PC withPIAyou will definitely enjoy a myriad of features and never have to worry about failed connection errors. If anything, this well-rounded VPN will streamline your connection, eliminate server buffering and ISP throttling and enhance your download speeds.
Packed with unlimited bandwidth and more than 3292 servers strategically placed across the globe,PIAwill let you choose the server closest to you, and route your traffic towards it via highly encrypted VPN tunnels.
2. Use Microsoft CHAP Version 2
VPNuses different protocols, and in order to fixConnectionfailedwith error 691, you need to use Microsoft CHAP Version 2. To do that, follow these steps:
After enabling Microsoft CHAP Version 2, check if the problem still appears.
3. Uncheck the Include Windows logon domain option
SometimesConnection failed with error 691messages can appear if yourVPNconnection isn’t configured properly, but you can fix that problem by disabling theInclude Windows logon domainoption.
To do that, follow these steps:
4. Change the LANMAN parameters
According tousers, you can fix the VPN error 691 on yourPCby simply changing the LANMAN parameters.
This can be done via the Group Policy Editor, a built-in tool on your Windows device. It is easy and perfectly safe to use.
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Press theWindows+Rkeys to open the Run dialog and typegpedit.mscin it.
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Click onOKto run the command.
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The Local Group Policy Editor will now start. In the left pane, go toComputer Configuration >Windows Settings> Security Settings >Local Policies> Security Options.
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In the right pane, locate and double-click onNetwork security: LAN Manager authentication level.
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Go to theLocal Security Settingtab. Choose toSend LM & NTLM responsesfrom the list. ClickApplyandOKto save the changes.
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Now double-click onNetwork Security: Minimum Session Security for NTLM SSP.
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Be sure to disableRequire 128-bit encryptionoption and enable theRequire NTLMv2 session securityoption.
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ClickApplyandOKto save the changes.
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Restart your PC.
5. Check if yourusernameand password are correct
SometimesConnection failed witherror691messages can appear if yourusernameor password isn’t correct. To ensure that your password is correct, we advise you to check if you have the CAPS LOCK option turned on.
In addition, be sure to enter your email address as yourusername.
6. Update Network drivers
The next thing we’re going to try is updating your network drivers. Here’s how to do that:
Update drivers automatically
If you don’t want the hassle of searching for drivers on your own, you can use a tool that will do this for you automatically. Of course, as you’re not able to connect to the internet at the moment, this tool won’t be useful.
However, once you get online, it will help you to keep all your drivers up to date, so you won’t be in this situation anymore.
An automatic driver updater tool will help you update drivers automatically and preventPCdamage caused by installing the wrong driver versions.
After several tests, our team concluded that this is the best-automatized solution.
⇒Get Outbyte Driver Updater
7. Check your connection’s security settings
Connectionfailedwith error 691messages that can appear if your security settings aren’t properly configured.
To fix this problem, you need to check your connection’s security settings by following these steps:
After making the necessary changes, check if the problem is resolved.
8. Leave the domain name blank for the outside connection
Users reported that theirVPNworks while using the internal network, however,Connectionfailedwith error 691appearing when trying to connect toVPNvia an Internet connection.
This is a strange problem, but it seems that the solution is rather simple. According tousers, they fixed the issue simply by leaving the domain name blank for the outside connection.
To fix the problem just enter yourusernameand password and leave the domain name blank. Click theConnectbutton and everything should work without problems.
9. Use the rasphone command
If you have problems connecting to theVPN, you might be able to fix them by using rasphone command. You can run this command by following these steps:
10. Check if there are other activeVPNconnections
Connectionfailedwith error 691messages can appear if there are active connections. To fix this problem, be sure to check if there are any otherVPNconnections running.
If so, be sure to disable these connections and check if that solves the problem.
11. Check your domain name
A fewusersreported that this issue occurs because your domain name isn’t correct. According tousers, the issue appears if your domain name uses the company.local format.
In order to fix the problem, you need to remove.localfrom the domain name. For example, if your domain name isCompany.localswitch it toCompanyand check if that fixes the issue.
12. Use a different Logon ID
SometimesConnectionfailedwith error 691messages can appear if your Logon ID profile is damaged. If that’s the case, create a new Logon ID and try using it instead.
13. Change yourusername
A few users reported thatConnection failed witherror691message appearing due to theirusername. According to them, bothusernameand password are correct, but the issue still appears. If you have the same problem, you might want to try adding the domain name to yourusername.
To do that, simply add@YourDomainNameto youruser name. For example, if your currentusernameisUsername, you need to change it toUsername@YourDomainName. After doing that, try to connect to theVPNagain.
14. Delete and add yourVPNconnection to fix error 691
If you’re getting aConnection failed witherror691messages, you can fix it simply by deleting and creating yourVPNconnection again. This is quite simple inWindows 10, and you can do it by following these steps:
After creating a newVPNconnection, try to connect to it and check if the issue still persists.
15. Use PAP instead of LDAP
Users reported that you can’t use the MS-CHAP v2 protocol with an LDAP server setup. By doing so, you’ll causeConnection failed witherror691messages to appear.
To avoid this problem, simply switch from the LDAP server setup to PAP and the problem will be fixed.
16. Add ports to WAN/virtual server port forwarding
This error can appear if you’re trying to use aVPNin your network. According to someusers, you can fixConnectionfailedwith error 691error message by adding ports to the WAN/virtual server port forwarding.
If you’re not a network administrator, be sure to contact your network administrator and ask him to make the necessary changes.
17. Contact your ISP
SometimesConnectionfailedwith error 691messages can be caused by problems with your ISP. A fewusersreported that the error was caused by their ISP, but after contacting the ISP the issue was resolved.
Connectionfailedwith error 691messages can prevent you from using yourVPN, and if you have this problem, we encourage you to try some of our solutions.
Let us know how it worked for you in the comments section below.
More about the topics:Fix VPN,VPN,VPN errors
Milan Stanojevic
Windows Toubleshooting Expert
Milan has been enthusiastic about technology ever since his childhood days, and this led him to take interest in all PC-related technologies. He’s a PC enthusiast and he spends most of his time learning about computers and technology.
Before joining WindowsReport, he worked as a front-end web developer. Now, he’s one of the Troubleshooting experts in our worldwide team, specializing in Windows errors & software issues.
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Milan Stanojevic
Windows Toubleshooting Expert
Before joining WindowsReport, he worked as a front-end web developer. Now, he’s specialized in Windows errors & software issues.
