VPN troubleshooting guide – How to solve common VPN problems

These days, Virtual Private Networks (VPNs) are indispensable. People around the world use them to access restricted content, keep their online activities private, and connect securely to work resources. But, like any complex technology, VPN tools can have problems that stop them from working as they should.

This guide goes over common VPN issues and provides simple troubleshooting steps to help you fix them quickly.

Understanding VPN connections

Before diving deep into troubleshooting, let's explore how a VPN works. A VPN creates a secure "tunnel" between your device and the internet. When you connect to a VPN, your internet traffic is encrypted and routed through this tunnel. Here’s a simplified, step-by-step breakdown of the entire process:

1. When you activate your VPN app, it connects to a VPN server. This server can be located in a different city or even country, depending on your choice. All your data from this point onwards flows through this server.
2. The VPN encrypts your data. This encrypted data can only be understood by the VPN server and the website you’re accessing, which protects your data from hackers.
3. As your data goes through the VPN server, the server replaces your real IP address with its own IP address. This is done to hide your real location, essentially making it look like you are browsing from the server’s location.
4. With the new IP address, your data is then sent from the VPN server to the website you’re trying to access. Since your data is encrypted, the website can’t trace your real location or identity.
5. The website responds to your request (e.g., loading a webpage) and sends data back to the VPN server.
6. The VPN server then sends the data back to your device through the secure tunnel.
7. Finally, the VPN app installed on your device decrypts the data. This allows you to see the content on your screen as if you were browsing directly, even though the data went through extra layers of security.

VPN connection issues

Let’s start by looking at common issues related to establishing VPN connections.

Unable to establish VPN connection

Description

This is when you can’t connect to the VPN server at all.

Symptoms

• The VPN app shows connection errors or times out.
• Your internet works, but the VPN won’t connect.

Troubleshooting

• Ensure that you have a stable and working internet connection.
• Double-check your username, password, or any authentication code if required.
• Try connecting to a different VPN server location.
• Restart your device and the VPN app.
• Temporarily disable any firewall or antivirus that may be blocking the VPN.
• Keep your VPN app updated to the latest version.
• Check that your VPN subscription is active.

VPN connection drops frequently

Description

The VPN connects successfully but disconnects unexpectedly during use.

Symptoms

• Frequent disconnections while using the VPN.
• Messages like “VPN connection lost” appear on your screen.

Troubleshooting

• Switch to a different VPN server, as some servers may simply be unstable.
• Test your internet connection to see if it’s dropping on its own.
• Check if your VPN app has an “auto-reconnect” option and enable it.
• Try changing the VPN protocol (e.g., switching from OpenVPN to IKEv2 or vice versa) in the VPN settings.
• Move closer to your Wi-Fi router or connect via ethernet for a more stable connection.
• Disable any “sleep” or “battery saver” modes that may be causing the connection to drop.

Server overload

Description

This happens when too many people are using the same VPN server, which can slow down or block connections.

Symptoms

• Slow speeds while connected to the VPN.
• VPN connection fails or disconnects when trying to connect to popular server locations.

Troubleshooting

• Choose a server in a less popular location to reduce chances of server overload.
• Use a server location closer to your actual location, as it may be faster.
• If possible, upgrade to a VPN plan that offers dedicated or premium servers.

Authentication failure

Description

The VPN app fails during authentication and the connection isn’t established.

Symptoms

• The VPN app shows an “authentication failed” or “invalid credentials” error.
• Connection attempts end without successful connections being formed.

Troubleshooting

• Double-check your username, password, and any additional authentication methods (like 2FA).
• Ensure that your subscription is up to date and your account is active.
• Try restarting the VPN app, and then try logging in again.

VPN fails to connect on mobile networks

Description

The VPN works on Wi-Fi but fails to connect on cellular or mobile data.

Symptoms

• Errors or timeouts appear when attempting a mobile data connection.

Troubleshooting

• Ensure that your mobile data connection is strong and not limited by any data-saving settings.
• Switch to a different VPN protocol, as some mobile networks may block specific protocols.
• Restart your device and try reconnecting to the VPN on mobile data.
• Contact your VPN provider’s support, as some services may have specific recommendations for mobile networks.

VPN performance issues

Next, let’s look at some frequently encountered VPN performance bottlenecks.

Slow VPN speeds

Description

Your internet connection becomes noticeably slower after connecting to the VPN.

Symptoms

• Slow loading times for websites or apps.
• Delays in streaming videos or loading online content.

Troubleshooting

• Switch to a VPN server that’s closer to your location to reduce latency.
• Connect via a different VPN protocol in the settings (e.g., try IKEv2 or WireGuard if available).
• If enabled, disable the “double VPN” option, as extra layers can slow down speeds.
• Check whether there are any background apps or downloads using bandwidth, and close them as needed.
• If you’re using Wi-Fi, consider switching to a wired connection for better stability.
• Upgrade to a VPN plan with better performance, if available.

Inconsistent VPN speeds

Description

The VPN speed fluctuates and makes it hard to maintain a stable connection.

Symptoms

• Speed drops and then suddenly picks back up while using the VPN.
• Video quality or audio cuts out intermittently.

Troubleshooting

• Try connecting to a different server, as some servers may have inconsistent performance.
• Check your internet connection without the VPN to see if the issue is with your ISP.
• Test different times of day when VPN traffic may be lower.
• Enable “split tunneling” if available. This allows only specific apps to use the VPN, which can reduce overall load.
• Make sure you have enough available bandwidth from your internet provider.

Unable to access certain applications on VPN

Description

Certain applications or websites don’t work properly when you’re connected to the VPN.

Symptoms

• The app fails to load or work as expected when VPN is active.
• You receive error messages about restricted access.

Troubleshooting

• Check if the app or website specifically blocks VPN connections (e.g., banking or streaming apps).
• Enable “split tunneling” if your VPN supports it, so only some traffic goes through the VPN.
• Switch to a different VPN server or protocol, as certain services may block specific IPs or protocols.
• Disable IPv6 in your device settings, as some VPNs don’t handle IPv6 traffic well.
• Update your VPN app to the latest version, as some apps may have new compatibility fixes.

VPN causes high CPU or battery usage

Description

The VPN app uses a lot of processing power or drains your battery quickly.

Symptoms

• Device slows down significantly after connecting to the VPN.
• Battery drains faster than usual.

Troubleshooting

• Switch to a more lightweight VPN protocol like IKEv2 or WireGuard if available.
• Close any unnecessary apps running in the background.
• Try connecting to a server with fewer load and users, as high load can cause more processing.
• Disable any unnecessary features like “double VPN” or “obfuscation”, which may increase CPU usage.
• Consider updating your device’s OS and VPN app, as new updates often have performance improvements.

VPN fails to bypass geographic restrictions

Description

The VPN doesn’t allow access to content that’s supposed to be available in other regions.

Symptoms

• Streaming services or websites still detect your real location.
• You’re unable to access geo-blocked content.

Troubleshooting

• Switch to a different VPN server in the desired location, as some servers may be blocked.
• Clear your browser’s cache and cookies, which may store location data.
• Try using a private or incognito browsing window to avoid location tracking.
• Upgrade to a VPN plan with servers dedicated to geo-unblocking (if available).

VPN security issues

Moving on, let’s discuss and dissect security related problems when using VPNs.

VPN blocked by firewalls

Description

Some networks, especially in workplaces or countries with strong censorship, block VPN connections.

Symptoms

• VPN won’t connect, or disconnects when trying to connect on certain networks.
• You receive error messages related to blocked traffic or restricted networks.

Troubleshooting

• Try using a VPN protocol that’s harder to detect, like WireGuard.
• Switch to an “obfuscated” or “stealth” server if your VPN app offers one; these are designed to bypass VPN blocks.
• If possible, use a different port that’s less likely to be blocked (e.g., port 443, which is used for HTTPS traffic).
• Consider switching to a mobile data connection if the Wi-Fi network blocks VPNs.
• Contact your VPN provider to see if they recommend specific settings for bypassing firewalls.

VPN logging data despite “no-log” policy

Description

Some VPN providers may still log user data, even if they claim a “no-log” policy.

Symptoms

• VPN client logs private data.

Troubleshooting

• Research your VPN provider to verify their “no-log” policy and check for third-party audits that confirm it.
• Look for VPN providers based in privacy-friendly countries that don’t require mandatory data logging.
• Use a multi-hop VPN feature if available, adding an extra layer of privacy by routing traffic through multiple servers.

VPN unable to block malware or ads

Description

The VPN fails to block unwanted content or protect against malware as expected.

Symptoms

• Ads or pop-ups still appear even when the VPN is on.
• No additional security features are working as expected.

Troubleshooting

• Check whether your VPN app includes ad-blocking or malware-blocking features, and make sure they’re enabled.
• Consider using a separate adblock or antivirus alongside your VPN for more protection.
• Update the VPN app to the latest version, as this may improve security feature functionality.
• Switch to a VPN server with lower load, as high-traffic servers may struggle with additional filtering.

VPN causing DNS leaks

Description

A DNS leak occurs when your DNS requests (website lookups) bypass the VPN.

Symptoms

• Websites or online tools show your ISP or true location.

Troubleshooting

• Run a DNS leak test to confirm whether your DNS requests are leaking.
• Manually set your DNS to a secure, public DNS provider (like Google or Cloudflare) in your network settings.
• Enable DNS leak protection in your VPN app, if available.
• Clear your device’s DNS cache to remove any stored DNS information from your ISP.
• Disable IPv6 on your device, as some VPNs don’t support secure DNS over IPv6.

Software and configuration issues

Sometimes the VPN software can encounter problems of its own. Let’s discuss how to troubleshoot them:

VPN client crashing or freezing

Description

The VPN app closes unexpectedly or becomes unresponsive.

Symptoms

• VPN app closes or freezes shortly after opening.

Troubleshooting

• Restart your device and try to reopen the VPN app.
• Make sure your VPN app is updated to the latest version; older versions may have bugs.
• If you are using a mobile app, clear the app’s cache and data in your device settings.
• Reinstall the VPN app to replace any corrupted files.
• Check if there are any software conflicts, such as other VPN or security apps running at the same time.
• If using Windows, try running the app in compatibility mode.

VPN configuration issues

Description

The VPN is not set up correctly, which can prevent it from working as expected.

Symptoms

• The VPN fails to connect or shows configuration errors.

Troubleshooting

• Review the VPN’s setup guide to ensure that all settings are entered correctly, especially for manual configurations.
• Double-check login credentials and any security keys or certificates that you are using.
• If your VPN requires manual DNS or proxy settings, make sure that these are configured correctly.
• Reset the VPN app to default settings and try reconfiguring it.
• For corporate VPNs, contact your IT team to verify the correct configuration.

VPN protocol conflicts or issues

Description

The VPN protocol isn’t supported or is causing connection issues.

Symptoms

• VPN fails to connect or is unstable on specific protocols.
• Certain protocols aren’t available in the app.

Troubleshooting

• Try switching to a different protocol in the VPN app settings (e.g., OpenVPN, IKEv2, or WireGuard).
• Make sure your network supports the chosen protocol (some networks block specific protocols).
• Update your VPN app to ensure compatibility with newer protocols.
• Check your firewall settings, as some may block certain protocols. If needed, adjust the settings to allow the VPN’s protocol.

VPN client connection issues after device sleep or hibernation

Description

The VPN disconnects or won’t reconnect after the device goes to sleep or hibernates.

Symptoms

• VPN connection is lost every time the device wakes up.
• The VPN app shows a connection error after resuming from sleep.

Troubleshooting

• Enable the “auto-reconnect” option in the VPN settings to restore the connection automatically.
• Disable any battery saver or power-saving modes that may affect VPN connections.
• Restart the VPN app after waking up the device to see if it reconnects.
• If the issue persists, contact the VPN provider for advice on how to overcome this problem.

VPN best practices

To steer clear of most of the aforementioned issues, here are some best practices to follow:

• Always go for a well-reviewed VPN provider with a strong privacy policy. Free or lesser-known VPNs may log your data or provide less security, so do some research before choosing one.
• Updates often include security improvements and bug fixes. So, make it a habit to update your VPN app as soon as an update or patch is rolled out.
• Enable features like kill switch, DNS leak protection, and strong encryption protocols (e.g., OpenVPN or WireGuard) for maximum security.
• Before accessing any sensitive data on public networks, double check your VPN connection, as these networks are often unsecured and prone to attacks.
• Select a server that is close to your location for better performance unless you need to connect from a specific country. Closer servers usually offer faster speeds.
• If available, enable split tunneling. With this feature, you can route only specific apps through the VPN while others use your regular connection.
• Some VPNs don’t handle IPv6 well, which can lead to IP leaks. If your VPN is incompatible with it, disable IPv6 from your network settings.
• If your VPN runs for long hours, periodically reconnect to refresh the connection and fix any small issues that may come up.
• Stick to one secure VPN at a time. When you run multiple VPN or proxy services simultaneously, it can create conflicts, slow down your connection, and lead to unexpected behavior.
• Use a dedicated VPN monitoring tool, like the one offered by Site24x7, to track the health and performance of your VPN connections in real time.

Conclusion

VPNs are a crucial technology with applications that cover personal privacy, secure business operations, and safe browsing on public networks. However, like you saw in this troubleshooting guide, VPN apps can sometimes run into issues. We hope that the insights shared in this guide will make it easier for you to troubleshoot these issues independently and enjoy a seamless VPN experience.