VPNs and antivirus tools both aim to protect you — but they don’t always get along. Here's why:

1. Antivirus Firewall Blocking VPN

Most antivirus firewalls are built to block unknown or untrusted apps — and that includes VPNs. Even if your VPN is safe, it may use ports or protocols that look suspicious.

Firewalls in AVG, Kaspersky, TrendMicro, or Windows Defender can block ports like 443 or 1194, which are common for VPNs like ExpressVPN, Surfshark, or Cisco AnyConnect.

This kind of interference is one of the most common reasons a VPN won’t connect. Whitelisting your VPN client in the firewall usually fixes it.

2. SSL/HTTPS Scanning

Some antivirus tools scan encrypted traffic. This interferes with VPN encryption, especially for ExpressVPN, Opera VPN, or browser-based VPNs.

3. Protocol or Port Restrictions

Antivirus programs may restrict protocols like OpenVPN or WireGuard, or block ports used by L2TP/IPSec, PPTP, or SSTP.

4. Web Advisor or URL Filtering

Antivirus browser plugins or web filters might flag VPN websites or block installations.

5. VPN Drops During Scans

If your VPN disconnects during antivirus scans, the issue is usually aggressive real-time protection or temporary firewall rules applied during scanning.

Here’s how to resolve the conflict without uninstalling your antivirus:

1. Add VPN to Antivirus Exclusions

Most antivirus tools allow you to whitelist or exclude apps from scanning or blocking.

• Windows Defender:
  Go to → “Virus & threat protection” → “Manage settings” → “Add or remove exclusions” → Add your VPN .exe file or folder.

• AVG:
  Settings → “General” → “Exceptions” → Add VPN path (e.g., ExpressVPN folder).

• ESET NOD32:
  Setup → Advanced Setup → Web Access Protection → Disable SSL filtering or add exceptions for your VPN.

• Kaspersky:
  Go to Network Settings → Uncheck SSL monitoring for port 443.

• Symantec / TrendMicro:
  Add VPN app to firewall exceptions and turn off web filtering for VPN-related domains.

2. Disable SSL/HTTPS Scanning

• SSL scanning interferes with VPN encryption.
  
  

• Look for options like “HTTPS scanning,” “SSL protocol filtering,” or “Encrypted traffic scan” and turn them off.

3. Allow VPN Through Antivirus Firewall

• Go to your antivirus’s firewall settings

• Find “Allowed apps” or “Exceptions”

• Add your VPN client (e.g., ExpressVPN, Cisco AnyConnect, etc.)

4. Reset Firewall to Default

If firewall rules are messy or unclear, resetting them can restore VPN functionality. Just be sure to re-add needed exceptions.

No. VPNs don’t block antivirus software. But they may encrypt traffic in ways that prevent antivirus tools from inspecting it. This isn’t harmful — it’s what VPNs are designed to do. If anything, your antivirus may limit the VPN, not the other way around.

Can Antivirus Cause VPN Leaks?

Yes — in rare cases. If an antivirus interrupts the VPN tunnel or kills the encrypted connection mid-session, your real IP can leak. This can happen during aggressive scans, firewall resets, or if the VPN lacks a kill switch.

Tip: Use VPNs that offer DNS leak protection and kill switch to stay safe.

Check If Your VPN Is Leaking

If your antivirus caused a VPN disconnect, you may have leaked data without knowing it. Use tools like VPNTest.pro to check:

• Is your real IP exposed?

• Are DNS or WebRTC leaks happening?

• Did your VPN drop and leave you unprotected?

This simple test shows you if your setup is working — and what’s leaking if it’s not.

Best Antivirus That Works With VPNs

If you want fewer problems, choose antivirus tools known to be VPN-friendly:

• Bitdefender – Reliable firewall + good app exclusions

• Norton 360 – Includes its own VPN (decent compatibility)

• Avira – Offers its own VPN or works fine with third-party tools

• Windows Defender – Works well after exclusions are added

Avoid overly restrictive suites unless you’re comfortable adjusting advanced settings.

VPN Still Not Working With Antivirus?

Try these steps:

• Reinstall the VPN after configuring antivirus exceptions

• Switch to a different protocol (e.g., from OpenVPN to WireGuard)

• Use a dedicated IP VPN to avoid blacklisted IPs

• Test the VPN on another device with the same antivirus

• Use mobile data as a quick check (to rule out firewall or DPI)

Antivirus Exceptions for VPN – Quick Setup Table

Antivirus tools are essential — but they can accidentally block VPNs, leaving you exposed or disconnected. The good news? You don’t have to choose between them. With a few simple tweaks, you can run both safely.

If your VPN is not working because of antivirus, follow the steps above and test again. And if you want a smoother setup, stick to VPN-compatible antivirus software that plays nice out of the box.

1. Does Windows Defender block VPN?

Yes, it can. Windows Defender Firewall may block your VPN if it doesn't recognize the app or its ports. Add your VPN to the Defender exceptions and allow it through the firewall to fix this.

2. Why does my VPN only work when antivirus is off?

If your VPN connects only when the antivirus is disabled, the antivirus is likely blocking the VPN’s traffic. You’ll need to whitelist the VPN or disable SSL scanning in the antivirus settings.

3. Can antivirus cause VPN to disconnect randomly?

Yes. Real-time protection or firewall scans in some antivirus tools can temporarily interrupt VPN tunnels, causing sudden disconnects or unstable sessions.

4. How do I whitelist my VPN in antivirus software?

Each antivirus is different, but the general steps are:

1. Open antivirus settings

2. Find “Exclusions” or “Exceptions”

3. Add your VPN’s .exe file or folder to the list

4. Save and restart both apps

5. Can I use antivirus and VPN at the same time?

Yes — and you should. Just make sure to configure both properly. Add the VPN to the antivirus exception list, disable conflicting filters (like SSL scanning), and test for leaks after setup.

6. How do I fix "VPN not connecting because of antivirus"?

Start by adding your VPN to the antivirus exception list, disabling SSL or HTTPS scanning, and allowing VPN ports through the firewall. If the issue persists, reset your firewall settings.

7. Can AVG antivirus block ExpressVPN?

Yes. AVG’s firewall or HTTPS scanner can block ExpressVPN traffic, especially if SSL scanning is turned on. To fix it, go into AVG settings, add ExpressVPN to the exceptions list, and disable HTTPS scanning. This will stop AVG from inspecting or blocking your VPN tunnel.

8. Why is Opera VPN not working with Symantec or TrendMicro?

Opera’s built-in VPN often triggers blocks in Symantec and TrendMicro antivirus tools. That’s because these programs aggressively filter encrypted browser traffic. To fix this, disable the web protection or browser filtering feature in your antivirus, or switch to a dedicated VPN app.

9. Is Gatech VPN Cisco AnyConnect blocked by antivirus?

Yes. Cisco AnyConnect VPNs used by Gatech and other universities rely on IPsec protocols, which some antivirus programs restrict. If your connection fails, check the antivirus firewall settings and allow IPsec or port 443. You may also need to add AnyConnect to your antivirus’s trusted apps.