A VPN is a virtual private network that protects your online privacy by masking your public IP address. VPNs are widely used today, and according to Statista, the global VPN market will reach $75.59 billion by 2027, reflecting the growing demand for online privacy and security.
VPNs are useful not only for data security but also for gaining the freedom to access restricted content, work remotely effectively, enjoy entertainment, travel, and more.
However, there's one important caveat: a VPN is only useful if it's working properly.
In this basic VPN guide, we'll cover the most common reasons for VPN failure and step-by-step solutions for VPN troubleshooting, both for the client and server.
The easiest way to find out if a VPN is working is to launch the VPN program, connect to a server in a different location — for example, another city, state, or country — and check your IP address. You can find or check your external IP address using various websites or by typing "my IP" into your browser's search bar.
Your internet service provider (ISP) typically assigns a public IP address that contains important information, such as your ISP details and approximate geographic location.
When a VPN is enabled, your public IP address will display different information for your ISP, city, region, and possibly even country. So, if you're in the US but using a VPN in the UK, your public IP address will show a UK location.
If you're using a VPN but still see information about your ISP and current geographic location, your VPN is likely not working properly.
Sometimes, even a reliable VPN can fail, or the VPN keeps disconnecting, due to client-side issues, server problems, or network-related factors. These problems can range from simple to more complex. Here's a list of the most common reasons why a VPN might stop working:
Understanding where the problem is coming from — whether it's your device, your local network, your internet provider, or the VPN server — will help you resolve the issue more quickly. This can be determined by running a few basic checks.
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Before moving on to deeper diagnostics and technical VPN troubleshooting, try these simple steps:
If your VPN still isn't working after completing these steps, it's time to move on to more detailed troubleshooting on the client or server side.
When your VPN stops working, the fastest way to fix the problem is to pinpoint the source. The key question is simple: is the problem client-side or server-side — specifically, is it with your device or the VPN server? Here's how to determine this step by step.
Try disabling the VPN and visiting a few websites.
Select and connect to a different VPN server.
Get dedicated resources and KVM isolation for experiments worldwide.
Use the same VPN account on another device or network.
Run a simple test:
ping server_ip
tracert server_ip (Windows) or traceroute server_ip (Linux/macOS)Interpreting the results:
Most VPN clients and servers create logs.
Client logs typically indicate issues with local configuration on the client side, but persistent connection drops or service outages often indicate server instability.
|
Symptom |
Probable Cause |
|
Internet outage even without a VPN |
Client-side |
|
Only one server is down |
Server-side |
|
VPN is working on a different device |
Client-side |
|
All users report issues |
Server-side |
|
Ping is completely broken |
Path to server or network |
In this section, we'll cover the most common VPN issues and the diagnostic methods used to resolve them. A table is provided to help you quickly determine whether a more thorough server check is needed or if a client-side fix is possible. We'll also take a closer look at two common causes of failures: DNS configuration errors and IP address conflicts. You'll also find information about VPN blocking by your internet service provider or network administrator, including when and why this happens, and what to do in such situations.
The following table helps you quickly determine whether the problem can be resolved on the client side or requires deeper server-level troubleshooting.
|
Problem |
Client-Side Troubleshooting |
Server-Side Troubleshooting (Advanced Troubleshooting) |
|
VPN won't connect to the server |
|
|
|
VPN is connected, but there is no internet access |
|
|
|
Slow VPN speed |
|
|
|
VPN keeps disconnecting |
|
|
|
Some websites aren't loading |
|
|
VPN issues with DNS settings and IP address conflicts deserve special attention. Troubleshooting client-side issues requires a bit more technical knowledge than simply rebooting the device.
One of the most common reasons a VPN connection appears to be configured, but websites cannot be accessed, is incorrect DNS configuration. If the VPN server is not responding or the client is using incorrect DNS settings, domain names may be blocked.
DNS issues include:
Solutions:
These issues can often be resolved by setting up trusted public DNS servers, such as 1.1.1.1 (Cloudflare) or 8.8.8.8 (Google), and clearing the DNS cache.
Setting up third-party DNS 1.1.1.1 (Cloudflare) or 8.8.8.8 (Google) helps bypass ISP blocks and speeds up website loading. This can be done in Windows/macOS via network settings, in Android/iOS via network settings or private DNS, and in Linux via resolv.conf.
To set up third-party DNS, follow these steps:
resolv.conf file:
sudo nano /etc/resolv.conf
nameserver 1.1.1.1nameserver 8.8.8.8To clear the DNS cache, follow these steps:
cmd and click OK.ipconfig /flushdns
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
sudo resolvectl flush-caches
or
sudo systemd-resolve --flush-caches
Congratulations! Your DNS cache has been cleared successfully.
If the VPN assigns an IP address that overlaps with your local network, IP address conflicts may also occur. To avoid routing conflicts, VPN subnets should be different from your local network ranges.
Otherwise, the system may incorrectly route network traffic, making VPN access unreliable or completely unavailable.
Typically, such conflicts can be quickly resolved by checking and changing the IP address range on both the server and client. The easiest way to check the IP address is through the command line.
To check the IP address range, open the command line on your device using the method you already know.
ipconfig /all (Windows)
ifconfig (macOS)
ip addr или ifconfig (Linux)However, if you need to change the IP address on your local network, you'll have to do it manually.
Solution:
Using Dynamic Host Configuration Protocol (DHCP) combined with different subnets for the VPN and local network is the best way to avoid manual IP changes. This automatically resolves most conflicts.
In some situations, a VPN works correctly, but access may be limited or blocked by your ISP or local network administrator.
This can happen in:
Solutions:
Knowing the source of a problem and fixing your VPN once is a good thing. Avoiding the need for repeated repairs is even better. Most VPN failures stem from common causes, such as outdated clients, overloaded servers, incorrect firewall rules, or improper DNS configuration. These issues can usually be avoided with regular maintenance, and a few preventive measures can significantly reduce the likelihood of future VPN failures.
Here are some recommendations to help you maintain the performance, security, and stability of your VPN when needed:
Regular maintenance and monitoring help detect problems before they impact your connection.
When VPS isn’t enough.
If you've completed all the basic and advanced troubleshooting steps but your VPN connection failed and still isn't working, it might be time to contact technical support.
When contacting support, it's helpful to provide the following information:
Detailed diagnostic information will help support specialists quickly identify the problem and offer an appropriate solution.
Sometimes the problem isn't with the VPN server configuration, but with its infrastructure. If your VPN server frequently experiences slow speeds, frequent disconnects, or unstable connections, it could be due to insufficient server or shared hosting resources. VPN performance can also be impacted by overloaded servers, limited network ports, or aggressive traffic shaping.
In such cases, the best and inevitable solution is to upgrade to a dedicated or more powerful VPS. This will help ensure stability, improve network throughput, and give you more control over firewall and network settings. A properly configured server with sufficient CPU, RAM, and network bandwidth ensures a reliable connection and consistent VPN performance.
Reliable dedicated and virtual private servers by is*hosting have premium customer support, constant quality control, over 50 thousand active customers, and more than 20 years of experience.
If your VPN stops working, don't panic. In most cases, the cause is a simple DNS issue, a blocked port, or a client malfunction. Start with basic checks and move on to more in-depth diagnostics if necessary. By applying a structured VPN troubleshooting strategy and maintaining a proper VPN configuration and infrastructure, most connection issues can be effectively identified and resolved.