Can't Ping Ubuntu VM Connected to VPN Provider: A Troubleshooting Guide

Abstract: Having trouble pinging your Ubuntu virtual machine (VM) connected to a VPN provider? Learn about the possible causes and troubleshooting steps to take, including forwarding LAN traffic through a VPN tunnel using strongSwan VPN server.

Created: 2025-01-09 by UserComp.com Editors

Title: Troubleshooting Guide for StrongSwan VPN Server Forwarding LAN Traffic with VPNTunnel Router

Introduction

This guide provides a comprehensive troubleshooting approach for issues encountered when forwarding LAN traffic using a VPNTunnel router with a StrongSwan VPN server. The guide covers key concepts, subtopics, and detailed steps to help you resolve common problems.

Prerequisites

To follow this guide, you will need two dedicated VPN servers for the VPNTunnel router and StrongSwan VPN server. Ensure that both servers are properly configured and running.

VPNTunnel Router Configuration
- Install and configure the VPNTunnel router software on your preferred platform.
- Configure the VPNTunnel router to act as a router and forward traffic to the StrongSwan VPN server.
StrongSwan VPN Server Configuration
- Install and configure StrongSwan VPN server on your preferred platform.
- Configure StrongSwan VPN server to accept incoming connections from the VPNTunnel router.

Troubleshooting

VPN Connection Issues

If you cannot establish a VPN connection between the VPNTunnel router and StrongSwan VPN server, check the following:

Verify that both servers are properly configured and running.
Check the VPN server logs for any error messages.
Ensure that the VPN server's firewall allows incoming connections from the VPNTunnel router's IP address.
If using IPsec, ensure that the correct encryption algorithms, authentication methods, and Diffie-Hellman group are configured on both servers.

LAN Traffic Forwarding Issues

If LAN traffic is not being forwarded correctly, check the following:

Verify that the VPNTunnel router is correctly configured to forward traffic to the StrongSwan VPN server.
Check the StrongSwan VPN server logs for any error messages related to incoming LAN traffic.
Ensure that the StrongSwan VPN server's firewall allows incoming LAN traffic from the VPNTunnel router's subnet.
If using IPsec, ensure that the correct ESP protocol is configured for LAN traffic.

Routing Table Issues

If routing table issues are causing problems, check the following:

Verify that the correct default gateway is set on clients connected to the VPNTunnel router.
Check the VPNTunnel router's routing table to ensure that routes for the StrongSwan VPN server's subnet are correctly configured.
Ensure that the StrongSwan VPN server's routing table correctly handles incoming LAN traffic.

References

StrongSwan VPN Server Documentation: https://www.strongswan.org/documentation/
VPNTunnel Router Documentation: https://www.vpnrouter.com/docs/
IPsec Tutorial: https://www.ipspace.net/IPsec_Tutorial

Summary

This troubleshooting guide covered common issues when forwarding LAN traffic using a VPNTunnel router with a StrongSwan VPN server. By following the steps outlined in this guide, you should be able to resolve most issues encountered during the setup and configuration process.

Tags: Ubuntu VPN Troubleshooting Networking

Latest News

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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...

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.

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?

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.