Windows Server 2012 L2TP VPN Connection Fails

Windows Server 2012: Randomly Failing to Connect L2TP VPN using Pre-shared Key

Abstract: This article explains how to troubleshoot and resolve issues with connecting Windows Server 2012 to a remote L2TP/IPSEC VPN using a pre-shared key, when the connection randomly fails.

Created: 2024-02-04 by

Introduction

In this article, we will discuss a common issue that users may encounter when trying to connect to a remote L2TP/IPSec VPN using a pre-shared key on Windows Server 2012. This issue can occur randomly, making it difficult to diagnose and resolve. We will cover the key concepts related to this problem and provide a detailed context to help you understand and troubleshoot it.

Background

L2TP/IPSec VPNs are widely used to provide secure remote access to corporate networks. They use pre-shared keys to authenticate the VPN clients and establish a secure connection. However, sometimes users may experience random connection failures when trying to connect to a remote L2TP/IPSec VPN using a pre-shared key on Windows Server 2012.

Key Concepts

L2TP/IPSec VPNs

L2TP/IPSec VPNs are a combination of two technologies: L2TP (Layer 2 Tunneling Protocol) and IPSec (Internet Protocol Security). L2TP provides the tunneling protocol, while IPSec provides the encryption and authentication. L2TP/IPSec VPNs are widely used to provide secure remote access to corporate networks.

Pre-shared Keys

Pre-shared keys are a type of shared secret that is used to authenticate the VPN clients and establish a secure connection. Both the VPN client and the VPN server must know the pre-shared key to authenticate each other and establish a secure connection. Pre-shared keys are typically configured manually on the VPN client and the VPN server.

Troubleshooting Randomly Failing L2TP/IPSec VPN Connections

If you are experiencing random connection failures when trying to connect to a remote L2TP/IPSec VPN using a pre-shared key on Windows Server 2012, there are several things you can try to troubleshoot the issue.

Check the Pre-shared Key

The first thing you should check is the pre-shared key. Make sure that the pre-shared key is correctly configured on both the VPN client and the VPN server. If the pre-shared key is incorrect, the VPN connection will fail.

Check the VPN Server

If the pre-shared key is correct, the next thing you should check is the VPN server. Make sure that the VPN server is running and that it is configured correctly. You can check the VPN server logs to see if there are any errors or issues that may be causing the random connection failures.

Check the VPN Client

If the VPN server is running and configured correctly, the next thing you should check is the VPN client. Make sure that the VPN client is running and that it is configured correctly. You can check the VPN client logs to see if there are any errors or issues that may be causing the random connection failures.

Check the Network

If the VPN server and the VPN client are running and configured correctly, the next thing you should check is the network. Make sure that the network is functioning properly and that there are no issues that may be causing the random connection failures. You can use network diagnostic tools to check the network for issues.

Code Blocks

VPN Client Configuration


# This is an example VPN client configuration

[VPN]
Name = My VPN
ServerAddress = vpn.example.com
Protocol = L2TP
Authentication = PresharedKey
PreSharedKey = mypresharedkey

[Interface]
Address = 10.0.0.2/24
Gateway = 10.0.0.1

VPN Server Configuration


# This is an example VPN server configuration

[VPN]
Name = My VPN
ServerAddress = vpn.example.com
Protocol = L2TP
Authentication = PresharedKey
PreSharedKey = mypresharedkey

[Interface]
Address = 10.0.0.1/24
  • L2TP/IPSec VPNs are widely used to provide secure remote access to corporate networks.
  • Pre-shared keys are a type of shared secret that is used to authenticate the VPN clients and establish a secure connection.
  • Random connection failures when trying to connect to a remote L2TP/IPSec VPN using a pre-shared key on Windows Server 2012 can be caused by incorrect pre-shared keys, issues with the VPN server or VPN client, or network issues.
  • To troubleshoot the issue, you should check the pre-shared key, the VPN server, the VPN client, and the network.

References

— end article —

Latest News

Generating SSH Key Failed on Windows 11 (Simplified Chinese)
Generating SSH Key Failed on Windows 11 (Simplified Chinese)

This article provides solutions for the issue of SSH key generation failure on Windows 11 in Simplified Chinese. Learn how to resolve this problem and continue with your Git installation.

Read More
Windows 11: Duplicate and Extend Displays in a Home Office Setup
Windows 11: Duplicate and Extend Displays in a Home Office Setup

Learn how to duplicate and extend displays in a home office setup using Windows 11. This guide provides step-by-step instructions to optimize your workspace comfort.

Read More
Increase Timeout Limit in Firefox
Increase Timeout Limit in Firefox

Learn how to increase the timeout limit in Firefox to avoid high network latency issues causing the browser to hit the timeout limit while loading pages.

Read More
Creating Non-Persistent Shadow Copy Backups on Windows 11 Pro
Creating Non-Persistent Shadow Copy Backups on Windows 11 Pro

Learn how to create non-persistent shadow copy backups on Windows 11 Pro using WSL and Google Cloud Storage, solving the issue of WSL seeing open Windows files locked.

Read More
HP ProLiant MicroServer Gen8: DHCP Server Not Pinging Gateway
HP ProLiant MicroServer Gen8: DHCP Server Not Pinging Gateway

This article provides a solution for connecting an HP ProLiant MicroServer Gen8 running a fresh install of Linux Mint 22.1, using an Ethernet cable previously used with an HP laptop, which has proven internet connectivity, but fails to connect with the DHCP server not pinging the gateway.

Read More
Disabling Tenor GIF selector window in Emoji picker on Windows 11
Disabling Tenor GIF selector window in Emoji picker on Windows 11

Learn how to disable the Tenor GIF selector window in the Emoji picker on Windows 11, which starts flashing distracting animations when invoked.

Read More
Troubleshooting Webcam Upgrade on Windows 11 N Pro
Troubleshooting Webcam Upgrade on Windows 11 N Pro

This article provides a solution for the error encountered while upgrading a computer running Windows 11 N Pro, as the upgrade is not officially supported due to the lack of TPM. The issue starts when attempting to launch the Windows Camera app.

Read More
Setting up Office PC Server with Raspberry Pi: Multihop SSH Tunnel Reverse Forward Tunnel
Setting up Office PC Server with Raspberry Pi: Multihop SSH Tunnel Reverse Forward Tunnel

Learn how to set up an Office PC Server with a Raspberry Pi using a Multihop SSH Tunnel Reverse Forward Tunnel. This guide will walk you through the process of connecting your home PC (192.168.1.42) to a Raspberry Pi and opening an SSH remote tunnel. Follow this tutorial to securely access your office server from home.

Read More
Why does the mouse cursor trail on older Windows versions?
Why does the mouse cursor trail on older Windows versions?

Older versions of Windows sometimes cause the mouse cursor to trail, leaving copies of the cursor on the screen as it moves. This can be a problem when the computer is running slowly.

Read More
Optimizing ChatGPT Web App Performance in Firefox
Optimizing ChatGPT Web App Performance in Firefox

This article provides tips and tricks to improve the performance of a ChatGPT web app in Firefox without losing functionality. Long conversations and slow typing input delays are common issues addressed in this article.

Read More
Troubleshooting HDR Luminance Levels Mapping/Scaling while Playing HDR on PC
Troubleshooting HDR Luminance Levels Mapping/Scaling while Playing HDR on PC

This article provides solutions for issues encountered while playing downloaded HDR content on PC, such as incorrect luminance levels, mapping, or scaling. Common problems include games and YouTube not supporting HDR, even when setup is correct.

Read More
Conditional Formatting: Chart Title Greyed
Conditional Formatting: Chart Title Greyed

This article explains how to use Conditional Formatting in a chart, but the chart title is greyed out. Here's how to resolve this issue...

Read More
VeraCrypt Dual Boot Setup Disappears After Windows Reinstallation
VeraCrypt Dual Boot Setup Disappears After Windows Reinstallation

This article provides a solution for the issue where the VeraCrypt dual boot setup disappears after a Windows reinstallation.

Read More
Options for Installing NVME PCIe Adapter on IBM System x3650 M3 Type 9745KPG
Options for Installing NVME PCIe Adapter on IBM System x3650 M3 Type 9745KPG

Recently purchased an old IBM System x3650 M3 Type 9745KPG without drives. Wanting to install an NVME PCIe adapter for read support. What are the options?

Read More
Transparent Selection in Microsoft Paint Windows 11
Transparent Selection in Microsoft Paint Windows 11

Learn how to use the Transparent Selection option in Microsoft Paint Windows 11 for seamless image editing. Follow this guide to make your editing experience more efficient.

Read More
Inspiron 155000 Black Screen Boot Loop
Inspiron 155000 Black Screen Boot Loop

A Dell Inspiron 155000 laptop is stuck in a boot loop while charging and downloading a file. The laptop returns 'Found laptop', and turning the charging lights blinks 3 amber and 1 white.

Read More
Check Bitvise SSH Server License Validity Period on Windows 10
Check Bitvise SSH Server License Validity Period on Windows 10

Bitvise SSH Server license has expired and the server stops working, causing loss of access to remote computers. Check the current license validity date to plan ahead.

Read More
Preserving Layers Saving in Microsoft Paint on Windows 11
Preserving Layers Saving in Microsoft Paint on Windows 11

Learn how to preserve layers when saving an image in Microsoft Paint on Windows 11 to avoid flattening and losing the ability to edit the image.

Read More
Change Time Windows CMD Without Admin Rights
Change Time Windows CMD Without Admin Rights

Learn how to change the system time in Windows CMD without requiring admin rights using GitHub's Action Runner and Clock Sync.

Read More
How to Transpose Rows/Columns in Notepad++ using Python Script Plugin
How to Transpose Rows/Columns in Notepad++ using Python Script Plugin

Learn how to transpose rows or columns in Notepad++ using the Python Script plugin. This article provides a step-by-step guide to install and use the plugin for efficient data manipulation.

Read More
File Complaint Expedia
File Complaint Expedia

Learn how to file a complaint with Expedia. This guide covers steps for filing a complaint on Linux, Windows, and MacOS platforms.

Read More
Unable to Connect Home Sky Broadband Network on Win10 Laptop: WiFi/Ethernet not valid IP configuration
Unable to Connect Home Sky Broadband Network on Win10 Laptop: WiFi/Ethernet not valid IP configuration

This article provides solutions for Win10 laptop users who are unable to connect their home Sky Broadband network due to the 'WiFi/Ethernet not valid IP configuration' error.

Read More
Change Visited Link Color in Firefox (Latest Update: April 2025, v138.0)
Change Visited Link Color in Firefox (Latest Update: April 2025, v138.0)

Learn how to change the visited link color in Firefox with the latest update (April 2025, v138.0). This article provides step-by-step instructions to customize your Firefox browser.

Read More
Resolved Dispute Expedia
Resolved Dispute Expedia

Learn how to resolve disputes with Expedia effectively. This article provides a step-by-step guide to help you through the process.

Read More
Since upgrading to Windows 11, how to use Ctrl-Alt-Delete to login?
Since upgrading to Windows 11, how to use Ctrl-Alt-Delete to login?

After upgrading to Windows 11, the Ctrl-Alt-Delete key combination no longer brings up the prompt to enter a PIN (logging into Windows). No indication is given when the keys are pressed.

Read More
Cron Won't Start VirtualBox VM: A Solution
Cron Won't Start VirtualBox VM: A Solution

In this article, we will discuss a solution to a common issue where Cron won't start a VirtualBox VM. This problem can occur on various operating systems, and we will provide a solution that should work across Linux, Windows, and MacOS.

Read More
Block Internet Access for VLAN using EdgeRouter X5
Block Internet Access for VLAN using EdgeRouter X5

This article will guide you on how to block Internet access for a VLAN using EdgeRouter X5. By the end of this article, you will learn how to isolate your printer from the Internet while connected to a specific VLAN.

Read More
Export Command Line Column Task Manager Data to CSV
Export Command Line Column Task Manager Data to CSV

Learn how to export the Task Manager's memory usage data to a CSV file using the command line. This guide covers Windows, Linux, and macOS.

Read More
Configuring OS/Browser to Open Certain File Extensions in Specific Websites (Browser-Specific) - Tech Support
Configuring OS/Browser to Open Certain File Extensions in Specific Websites (Browser-Specific) - Tech Support

Learn how to configure your operating system and browser to open specific file extensions in certain websites, making it easier to handle old computers and access modern web applications.

Read More
Recommendation for Weird/Big Multi-Monitor KVM Setup
Recommendation for Weird/Big Multi-Monitor KVM Setup

This article provides a recommendation for a weird/big multi-monitor KVM setup using a Thunderbolt port and drive. It will guide you through the process of setting up a desktop replacement with six screens, ensuring a seamless and efficient work environment.

Read More
Running rsync on Windows using MSYS2: Source/Dest Path Formats
Running rsync on Windows using MSYS2: Source/Dest Path Formats

This article provides instructions on how to use rsync on Windows with MSYS2, converting Windows source/dest paths to a Linux-compatible format. This allows syncing through rsync.

Read More
Automating Keyboard Shortcuts with PowerShell and Task Scheduler
Automating Keyboard Shortcuts with PowerShell and Task Scheduler

Learn how to automate keyboard shortcuts using PowerShell and Task Scheduler. This guide will show you how to create and schedule a PowerShell script that sends specific keystrokes to open applications.

Read More
Splitting Multiline Text Words - PowerShell
Splitting Multiline Text Words - PowerShell

Learn how to split multiline text words using PowerShell. This article provides a simple solution to the problem of splitting text at specific characters, even when they are followed by whitespace. Try the provided script to effortlessly split your multiline text.

Read More
Creating a User-Defined Snippets Repository in Kate
Creating a User-Defined Snippets Repository in Kate

This article provides a step-by-step guide on creating and setting up a user-defined snippets repository in Kate, a powerful and feature-rich text editor. Follow these instructions to streamline your coding experience.

Read More
Creating a Spreadsheet List with Addresses and Tickbox for Payment Received
Creating a Spreadsheet List with Addresses and Tickbox for Payment Received

Learn how to create a spreadsheet list with addresses and a tickbox for payment received. This tutorial will guide you step-by-step to organize your data effectively.

Read More