Fix: “PPP Link Control Protocol Was Terminated’ Error on Windows

The ‘PPP Link Control Protocol Was Terminated‘ error typically occurs when users attempt to connect to an existing VPN network or when attempting to establish a dial-up connection. This problem is known to occur on both Windows 10 and Windows 11. 

‘PPP Link protocol was terminated’ error on Windows

After we’ve investigated this particular issue thoroughly, we realized that there are actually several different causes why you might experience this error code occurring on Windows 10 or Windows 11:

  • Incorrect option settings – As it turns out, more often than not, this problem will occur due to wrong credentials being saved for your network. If this scenario is applicable, you can fix the issue by accessing the Network connections menu and forcing your OS to remember the current credentials before attempting to connect to the VPN network once again.
  • Microsoft CHAP Version is disabled in VPN settings – If you are experiencing this problem while attempting to connect to a previously configured VPN network, the first thing you should do is ensure that the Microsoft CHAP version is enabled for this particular connection. If this protocol is disabled, go to the Security tab and enable Microsoft CHAP Version 2. 
  • Multi-link is enabled for single-link connection – This problem can also occur due to a flaw inside the PPP (Point to Point) protocol. In order to fix this problem, you need to access the Properties screen of the problematic connection and uncheck the option named “Negotiate multi-link for single-link connections”.
  • Data encryption is set to optional – Another scenario that might cause this problem is a scenario in which the current connection is configured to use options data encryption (which ends up confusing for every network protocol used). To fix this problem, you need to modify the current Data encryption.
  • Firewall interference – Keep in mind that both Windows Firewall and 3rd party firewalls are known to sometime interfere with VPN connections and in some cases even make the connection unusable. To test out and see if this theory is correct in your case, temporarily disable your Windows Firewall or disable/uninstall a 3rd party equivalent and see if the ‘PPP Link Control Protocol Was Terminated’ error is now fixed. 
  • Improper dial-up connection – If you’re experiencing this problem while attempting to dial-up a PPP connection, there are some modifications you need to do. First, you need to disable multi-link for single link connections, then force the encryption on your connection. 

Now that we went over every potential reason why you might experience this problem, let’s get to the fixing part. Below you’ll find a list of verified fixes that will allow you to pinpoint and resolve the ‘PPP Link Control Protocol Was Terminated‘ error.

1. Modify the Option Settings

As it turns out, the majority of the time, this problem is caused by incorrect network credentials being saved. If this is the case, you can resolve the problem by going to the Network connections menu and forcing your OS to remember the current credentials before reconnecting to the VPN network.

Several affected users have confirmed that they manage to fix the problem by accessing the Network Connnections menu and forcing the VPN connection to ‘forget the credentials’ before saving the changes and attempting to connect through it once again.

For step by step instructions on how to do this, follow the instructions below:

  1. Press Windows key + R to open up a Run dialog box. 
  2. Next, type ‘ncpa.cpl’ inside the Run dialog box and press Ctrl + Shift + Enter to open up the Network Connections menu with admin access. 
    Accessing the Network Connections menu
  3. When you’re prompted by the User Account Control (UAC), click Yes to grant admin access. 
  4. Once you’re finally inside the Network Connections menu, right-click on your VPN network and then click on Properties from the context menu that just appeared. 
    Accessing the Properties screen of the VPN network
  5. Once you’re inside the Properties screen, use the ribbon menu at the top to select Options.
  6. Inside the Options screen, uncheck the box associated with the Remember my credentials.
  7. Save the changes by clicking Ok, then you can safely close the Network Connections window. 
  8. Attempt to connect to the VPN section once again and see if the problem is now fixed.

If the same ‘PPP Link Control Protocol Was Terminated’ error is still occurring, move down to the next method below. 

2. Enable Microsoft CHAP Protocol in VPN Settings

If you are experiencing the ‘PPP Link Control Protocol Was Terminated’ error while attempting to connect to a VPN network via the native functionality, you are not the only one. 

On Windows 10 and Windows 11, this is the most common cause for this particular error:

Can’t connect to *VPN Network Name*
The PP link protocl was terminated.

If you find yourself in the same scenario, you’ll be please to know there’s an easy fix. You’ll need to access the Network Connections menu and modify a few security options belonging to your VPN connection – you can find these inside the Properties screen of your VPN.

Note: All you need to do is to allow a hidden protocol called Microsoft CHAP Version 2 (MS-CHAP v2)

For specific instructions on how to do this, follow the steps below:

  1. Press Windows key + R to open up a Run dialog box. 
  2. Next, type ‘ncpa.cpl’ inside the Run dialog box and press Ctrl + Shift + Enter to open up the Network Connections menu with admin access. 
    Accessing the Network Connections menu
  3. When you’re prompted by the User Account Control (UAC), click Yes to grant admin access. 
  4. Once you’re finally inside the Network Connections menu, right-click on your VPN network and then click on Properties from the context menu that just appeared. 
    Accessing the Properties screen
  5. Once you’re inside the Properties screen, use the tab at the top to click on Security. 
  6. Next, once you’re inside the Security tab, scroll down to the bottom of the screen and select the Allow these protocols (under Authentication). 
  7. Once the Allow these protocols toggle is selected, check the box associated with Microsoft CHAP Version 2 (MS-CHAP V2).
    Enable the Microsoft CHAP Version 2
  8. Click OK to save the changes, then restart your PC and attempt to connect to the same VPN that was previously triggering the ‘PPP Link Control Protocol Was Terminated‘ error.

If this scenario was not applicable as you’re experiencing this error while attempting to connect to a dial-up connection, move down to the next method below. 

3. Disable Multi-Link for Single-Link Connection

If you are experiencing this error while attempting to connect to a dial-up connection (for whatever reasons), you will most likely see Error 734. In this particular scenario, the problem is most likely occurring because Multi-link negotiation is turned on for a single-link connection.

Update: Another viable scenario that might cause the ‘PPP Link Control Protocol Was Terminated‘ error while you try to connect to a dial-up connection is having the dial-up connection security configuration improperly configured or configured to require a secured password. 

If one of the scenarios described above is applicable, follow the instructions below to fix the problem:

  1. Press Windows key + R to open up a Run dialog box. 
  2. Next, type ‘ncpa.cpl’ inside the Run dialog box and press Ctrl + Shift + Enter to open up the Network Connections menu with admin access. 
    Accessing the Network Connections menu
  3. When you’re prompted by the User Account Control (UAC), click Yes to grant admin access. 
  4. Once you’re finally inside the Network Connections menu, right-click on your VPN network and then click on Properties from the context menu that just appeared. 
    Accessing the Properties screen
  5. Once you’re inside the Properties window, click on the Options tab and click on PPP Settings from the menu underneath.
  6. After you’re finally inside the PPP Settings panel. go ahead and uncheck the box associated with “Negotiate multi-link for single-link connections”.
  7. Click Ok to save the changes, then click on Ok once again to save the changes.
  8. Finally, close the window and attempt to connect to the VPN connection once again.

If the problem is still occurring, move down to the next method below. 

4. Force Data Encryption 

Another circumstance that could create this issue is if the current connection is configured to employ data encryption options (which ends up confusing for every network protocol used). You must change the current Data encryption to resolve this issue.

Several affected users have confirmed that the ‘PPP Link Control Protocol Was Terminated‘ error was finally fixed after they modified the Properties screen of the VPN network and force it to always require encryption. 

If you’re looking for specific instructions on how to do this, here’s what you need to do:

  1. Press Windows key + R to open up a Run dialog box. 
  2. Next, type ‘ncpa.cpl’ inside the Run dialog box and press Ctrl + Shift + Enter to open up the Network Connections menu with admin access. 
    Accessing the Network Connections menu
  3. When you’re prompted by the User Account Control (UAC), click Yes to grant admin access. 
  4. Once you’re finally inside the Network Connections menu, right-click on your VPN network and then click on Properties from the context menu that just appeared. 
    Accessing the Properties screen
  5. Once you’re inside the Properties screen, click on the Security tab and look for the option named Data encryption.
  6. When you see it, modify the drop-down menu to Require encryption (disconnect if server declines).
  7. Click Ok to save the changes, then reboot your computer. 
  8. Repeat the action that was previously triggering the ‘PPP Link Control Protocol Was Terminated‘ error and see if the problem is now fixed.

If the problem is still not fixed, move down to the next method below.

5. Disable the active firewall

Keep in mind that both Windows Firewall and third-party firewalls have been known to interfere with VPN connections, making them ineffective in some situations.

To determine if this theory is right in your instance, briefly disable or uninstall your Windows Firewall, or a third-party equivalent, and see if the ‘PPP Link Control Protocol Was Terminated’ error has been resolved.

It’s possible that your firewall or antivirus software is interfering with your ability to connect to your game. The problem could be resolved by adding your game to the firewall’s white list. If not, get assistance from the firewall’s manufacturer.

Despite the fact that this problem is far more widespread with third-party antivirus software, we did locate a few user reports of it occurring with Windows Firewall.

If you’re in this predicament and think your firewall is to blame, you may rapidly test that theory by turning off any firewall functionality that’s currently running.

Disabling the 3rd party firewall

If you’re using a third-party firewall, disable it for the time being before rebooting and reinstalling the failed Windows Update.

Note: Depending on the tool, the exact procedures for disabling your third-party firewall will differ. Consult the official documentation for detailed information on disabling your 3rd party firewall’s real-time protection.

If you’re using Windows Firewall, however, follow the steps below to temporarily disable Windows Firewall:

  1. Press the Windows key + R to open the Run dialog box.
  2. Then type ‘ms-settings:windowsdefender’ into the text box and press Enter to open the Windows Defender Security Center window.
    Accessing the Windows Defender
  3. Select Yes to grant admin access if the User Account Control (UAC) prompts you.
  4. Once you’re in the Windows Security panel, click Firewall & Network Protection in the left-hand pane. 
    Accessing the Firewall and Network protection menu
  5. Select the currently active network from the Firewall & Network Protection menu, then scroll down through the list of settings to disable the Windows Defender Firewall toggle.
    Disable the Windows Defender firewall
  6. Once the firewall has been disabled, repeat the action that was previously causing the ‘PPP Link Control Protocol Was Terminated‘ error and see if the issue has been resolved.
ABOUT THE AUTHOR

Kamil Anwar


Kamil is a certified MCITP, CCNA (W), CCNA (S) and a former British Computer Society Member with over 9 years of experience Configuring, Deploying and Managing Switches, Firewalls and Domain Controllers also an old-school still active on FreeNode.