Avast Blocking Vpn

Tech & Gaming
1
VPN kept dropping immediately after connecting and the logs pointed to Avast as the cause. Confirmed it by disabling Avast — VPN connected fine. Here's everything I went through to actually fix it without turning Avast off permanently.

Avast has a few security layers that all touch network traffic. Any one of them can interfere with a VPN:

  • Web Shield — inspects outgoing traffic and can interrupt VPN handshakes
  • Firewall — may not have a rule permitting your VPN’s executable
  • Real Site — intercepts DNS queries before they reach your VPN’s DNS resolver

Step 1: Confirm It’s Actually Avast

Right-click the Avast icon in the system tray > disable it for 10 minutes > try connecting your VPN. If it connects, Avast is confirmed. Good to know before going through the steps below.

Step 2: Add the VPN as a Firewall Exception

  1. Menu > Settings > Protection > Firewall > Application rules
  2. Find your VPN app or click Add application and browse to its executable
  3. Set to Allow for both incoming and outgoing
  4. Apply

Step 3: Add the VPN to General Exceptions

This covers all Avast components, not just the Firewall.

  1. Menu > Settings > General > Exceptions
  2. Add exception > browse to the VPN’s main executable
  3. Optionally add the full installation folder as a path exception

Step 4: Disable Real Site

Real Site intercepts DNS queries and routes them through Avast’s servers. If your VPN handles its own DNS resolution, this breaks it.

Menu > Settings > Protection > Core Shields > find Real Site > toggle off.

Step 5: Check VPN Port Rules

If your VPN uses specific ports (e.g. UDP 1194 for OpenVPN, UDP 51820 for WireGuard), Avast’s Firewall may be blocking those ports. Check your VPN provider’s docs for which ports it uses, then verify they’re permitted in Firewall > Network rules.

Step 6: Look for a VPN Compatibility Setting

Newer versions of Avast sometimes have a dedicated VPN passthrough or VPN compatibility mode. Worth checking under Settings or Firewall advanced options.

Step 7: Update Avast

Some VPN conflicts are bugs in specific versions that have been patched.

Menu > Settings > Update

One Thing to Note

After making any of these changes, re-enable everything fully and restart before testing. A fix that only works with Avast partially disabled isn’t a real fix.

2

Real Site was my problem. silently rerouting DNS without being obvious about it. disabling just that feature rather than all of Avast sorted it.

3
Doing the quick disable test first is worth it before going through all the exception steps. Saved me from doing all this on the wrong problem once.
4

had to do both the firewall rule AND the general exception to get mine working. one without the other wasn’t enough.

5
worth checking if your VPN provider has Avast-specific setup notes. some of them publish these and they include the exact paths and port numbers, which saves a lot of time.