Are you a frequent VPN user? If the answer is yes, then recently, you might have come across this error message “the L2TP connection attempt failed because the security layer encountered a processing error”. Are you too looking for ways to solve this error then you have reached the right article. In this article, we will discuss the error, why it is occurring, and various solutions. Know how to Fix the Error Code 15 This Request Was Blocked By The Security Rules, Just by clicking here!
Table of Contents
What Is A VPN?
A Virtual Private Network (VPN) is an encrypted connection that helps to protect anonymity and privacy over the internet. You can secure your network through a VPN connection, prevent data throttling, avoid bandwidth throttling, and achieve network scalability.
Check out: The Most Appropriate VPN Software Solutions for Software Developers
What Is An LT2P Connection?
Layer 2 Tunneling Protocol (LT2P) is a tunneling protocol used to support VPN and other private networks. It must rely on an encryption protocol to pass within the tunnel to ensure security and privacy.
What Are The Causes Of LT2P Connection Attempt Failure Error?
Listed below might be a few causes why you might be facing this error
Corrupted Network Drivers
The network drivers installed on your computer might be corrupted.

Hence it might have triggered this error. You can reinstall the corrupted drivers and check if the error is fixed.
Microsoft CHAP V2 Protocols Disabled
In some instances, the error might occur because the Microsoft CHAP v2 protocol is disabled inside the VPN Connection’s properties.

So go ahead and enable the protocols and check if the error is fixed.
What Are The Various Solutions To Solve The LT2P Connection Attempt Failure Error?
We have listed 5 methods in which you can fix your connection
Solution 1: Enable The Microsoft CHAP V2 Protocol
Follow the steps below to do so:
1. Simultaneously press the “Window + R” keys combination on your keyboard to open the “Run” window.
2. Once the box opens, type “ncpa. CPL” and hit the “Enter” key.
3. It opens the Network Adapter Settings. Now right-click on your VPN connection and select “Properties” from the menu.
4. Click on the “Security” tab next and then click on the circle in front of the “Allow these protocols.”
5. Next, checkmark or enable the “Microsoft CHAP Version 2 (MS-CHAP v2)” box.

6. Now click on “Ok.” Now restart your computer or laptop and reconnect your VPN to check if the issue is resolved.
Solution 2: Enable LCP Protocol Extension
Follow the steps below to do so:
1. Simultaneously press the “Window + R” keys combination on your keyboard to open the “Run” window.
2. Once the box opens, type “ncpa. CPL” and hit the “Enter” key.
3. It opens the Network Adapter Settings. Now right-click on your VPN connection and select “Properties” from the menu.
4. Next, click on the “Options” tab and further click on “PPF Settings…”.
5. Now, checkmark the box in front of “Enable LCP Extensions” and then click on “Ok.”

6. Now restart your computer or laptop and reconnect your VPN to check if the issue is resolved.
Solution 3: Restart The IPSec Service
Follow the steps below to do so:
1. Simultaneously press the “Window + R” keys combination on your keyboard to open the “Run” window.
2. Once the box opens, type “services. MSC” and hit the “Enter” key.
3. It opens the Service manager. Now locate the “IKE and AuthIP IPsec Keying Modules” service and then right-click on it
4. Next select “Restart” from the menu. Then again, right-click on it and select “Properties.”
5. Click on the “General” tab and next click on the dropdown next to “Start-up type.”

6. Next select “Automatic” from the menu. Now save the changes made by clicking on the “Apply” button.
7. Now repeat the whole process for the “IPsec Policy Agent” service

Then restart your computer or laptop and reconnect your VPN to check if the issue is resolved.
Solution 4: Update Windows
Follow the steps below to do so:
1. Simultaneously press the “Window + I” keys combination on your keyboard to open “Settings.”
2. Now search for the “Update & Security” option and then click on it.
3. From the left-hand side column, select the “Windows Update” option.
4. Click on the “Check for updates“ button. If there are any new updates available, then download them. It is advised to keep updating windows to avoid such issues.

5. Next, restart your computer or laptop and reconnect your VPN to check if the issue is resolved.
Solution 5: Reinstall The Network Drivers
Follow the steps below to do so:
1. Simultaneously press the “Window + X” keys combination on your keyboard and then go ahead and select “Device Manager” from the list of options.
2. Now scroll further down to “Network adapters.” Next, click on it to see its contents.
3. Next, right-click on your installed network drivers and then select “Uninstall driver” from the menu to uninstall them.
4. Now restart your computer or laptop and launch the device manager.
5. Next, click on the “Scan for hardware changes” button, which you can find at the top middle of the screen.

6. Now, a window will detect all missing drivers and then automatically install all those drivers on your computer or laptop.
7. Once done, check if the error is resolved.
See also: 7 Best VPN for Mac in 2023 (With Pros & Cons)
Conclusion
We hope that the article was helpful and you were able to fix your VPN. Follow the website for more such articles. We hope you found the perfect fix for ‘ l2tp connection attempt failed because the security layer encountered a processing error ‘.

Gravit Sinha: Founder of ValidEdge, a problem-solving website, driven by his lifelong passion for fixing issues.