When setting up a VPN, things can go wrong in a few common patterns. The VPN server could be unreachable, which causes the VPN tunnels to fail. Or, you may not be able to establish the connection because the remote server is non-responsive.
In this case, specifically, the connection generally gets interrupted due to a poor connection which results in packet loss. We’ve detailed other reasons for this error and how you can troubleshoot them in the sections below.
Why Is The Connection Getting Interrupted?
Aside from internet latency, it’s also likely that the VPN server you’re trying to connect to has reached max capacity. The connection limit scales according to the available resources (bandwidth, processing power, servers, etc.). So, it’s hard to give a flat number, but as a reference, users have reported the connection limit to be as low as 5 connections at a time. Other probable causes include:
- Misconfigured VPN settings
- IP Packet Filtering
- Proxies
- Firewall
How to Fix the VPN Connection Issue?
Several users have reported that simply restarting the PC and router resolved this issue for them. As such, we recommend that you do the same before proceeding to the main solutions.
Check Connection Strength
As stated by the error message itself, the interruption often happens due to a poor internet connection. If you’re on WiFi, you should first ensure the WiFi signal is strong. Switching to Ethernet generally helps with the connection stability as well.
Of course, Ethernet connections aren’t immune to connection issues. As such, we recommend checking your connection strength with a ping test. Here are the steps to do so:
- Press Win + R, type
cmd, and press Enter. - Enter
ipconfigand note the Default Gateway.
- Type
ping defaultgateway -t -l 10000, replacedefaultgatewaywith the IP from the previous step, and press Enter.
- After around 15 pings, press CTRL + C to stop the test and view the result.
If your average ping is much higher than 15ms, or there’s some packet loss, this indicates the connection between your PC and router is facing some problems. In this case, troubleshooting the connection would be the best way to resolve the issue with the VPN.
Restart Remote Services
VPNs require the RasMan and RRAS services to be running. Even when they were already running, restarting them helped resolve the issue for some users. Here’s how you can do the same:
- Press Win + R, type
services.msc, and press Enter. - Select the Remote Access Connection Manager (RasMan) service and press Start / Restart.
- On the host server, select the Routing and Remote Access (RRAS) service similarly and Start / Restart it.
Check VPN / Firewall Configuration
Users often select the wrong tunneling protocol when setting up the VPN. Even when the correct protocol is selected, the firewall may block the necessary ports, which can also lead to the VPN connection issue. Here’s what you can do in such cases:
- Press Win + I and go to Network & Internet > VPN.
- Click on the VPN and select Advanced Options.
- Click on Edit next to connection properties.
- The VPN type may be set to automatic. This is generally fine, but as you’re having connection issues, it’s best to manually select the tunnel type specified by your VPN provider and press Save.
You should check a few things depending on which tunneling protocol you use:
- PPTP
Ensure that the firewall isn’t blocking port TCP 1723 and GRE Protocol 47. - L2TP/IPsec
Ensure that the firewall isn’t blocking port UDP 1701, and that the correct pre-shared key or machine certificate is present on the client and server. - SSTP
Ensure that a valid machine certificate and trusted root certificate are installed on the server and client machines, respectively. - IKEv2
Ensure that the firewall isn’t blocking UDP port 500 and 4500. Additionally, check that the correct machine certificate is present on both the client and server machines.
If you have to open the ports manually, here’s what you can do:
- Press Win + R, type
control firewall.cpl, and press Enter. - Click on Advanced Settings from the left pane.
- Click on Inbound Rules and press New Rule.
- Select Port > TCP or UDP and enter the value for specific local port.
- Select Allow the Connection and press Next > Next.
- Enter a name and description for this rule and press Finish.
Uninstall WAN Miniports
An RRAS connection is usually a dedicated connection in the form of a WAN adapter installed on the PC. Uninstalling the drivers for these WAN adapters has resolved the issue for numerous users. As such, we recommend trying the same with the following steps:
- Press Win + X and select Device Manager.
- Expand the Network Adapters section, right-click WAN Miniport (IP), and press Uninstall Device.
- Repeat this for WAN Miniport (IPv6) and your tunneling protocol type.
- Restart your PC and check if the issue is resolved.
Check VPN Passthrough
VPN Passthrough allows the VPN traffic from your device to pass through the router. If this feature is disabled, you won’t be able to establish the VPN connection. Here’s how you can ensure this isn’t the issue in your case:
- Launch a web browser and access the router settings page.
- Open the Security or similar tab and click on VPN Passthrough.
- Ensure the following protocols are enabled:
IPSec Passthrough
PPTP Passthrough
L2TP Passthrough
- After making the changes, press Save and check if the issue is resolved.
