Could my firewall be blocking my internet connection?

Few things are more frustrating than having “full signal” WiFi… and absolutely no internet to show for it.

Pages won’t load. Apps refuse to function. Your laptop insists everything is connected, yet nothing works. At this point, it’s only natural to start eyeing your firewall suspiciously.

But what is a firewall, anyway?

A firewall is essentially an online security gatekeeper. It monitors traffic going in and out of your network and decides what’s allowed through and what’s getting blocked.

Firewalls exist to protect you from:

• Malicious websites
• Hacking attempts
• Unauthorised access to your devices

They can live in a few different places:

• Built into your router
• Installed on your computer or mobile device
• Added by antivirus or security software

When they’re working properly, you don’t notice them at all. When they’re not… things can grind to a frustrating halt.

You probably already have an internet firewall in place, even if you’ve never set one up yourself. In fact, it’s quite difficult not to have a firewall these days. If your router came from your broadband provider, it almost certainly includes a built-in firewall that quietly filters traffic in the background. 

Likewise, both Windows and macOS come with their own firewalls that are enabled by default, such as Windows Defender Firewall or the macOS firewall, which help block unwanted connections. 

On top of that, many antivirus software packages like Norton, McAfee, or Bitdefender include their own firewall features as part of the security suite.

In other words, having a firewall is completely normal, and it’s a good thing! Firewalls play a vital role in keeping your devices and data safe. Problems only tend to arise when firewall settings become too strict, when multiple firewalls are running at once, or when security rules conflict with each other and accidentally block legitimate internet traffic.

Signs your firewall might be blocking your internet

A firewall issue often feels different from a total outage. Common clues include:

• WiFi says “connected”, but websites won’t load
• Some apps work, others don’t
• One device connects fine while another can’t
• The internet works when the firewall is turned off (temporarily)
• Certain websites or services are blocked entirely

How do I check my internet firewall settings?

Here’s how to check your firewall settings, whether you have a Windows firewall configuration or another:

1. Check your device firewall first

On most systems:

• Windows firewall settings: Search and open Windows Defender Firewall → Check “Allow an app through firewall”. That should do the trick if a Windows firewall is blocking incoming connections. 
• Mac network settings: System Settings → Network → Firewall. Check the control panel for apps or services marked as “blocked” that shouldn’t be.

2. Check your security software

Third-party antivirus programs often include their own firewalls, and sometimes they’re more aggressive than your system’s default one.

Open the software and look for:

• Firewall rules
• Network protection settings
• “Blocked connections” or alerts

This is a very common cause of internet issues, especially after updates.

3. Check your router firewall

Most routers come with a built-in firewall that’s switched on by default. This firewall sits between your home network and the wider internet, filtering incoming and outgoing traffic to block anything that looks suspicious. In most cases, it works quietly in the background and never causes problems.

However, if certain settings have been changed, the router firewall can sometimes become too restrictive and start blocking legitimate internet traffic.

To check if this is the issue:

1. Log into your router (often by accessing 192.168.1.1 or 192.168.0.1 in your browser)
2. Look for Firewall, Security, or Advanced Settings
3. Check for blocked services, ports, or devices

It’s important to be cautious when you adjust firewall settings at this level. Your router firewall protects every device connected to your network, so disabling it entirely or changing settings without understanding them can reduce your overall security. If you’re unsure, it’s best to review settings carefully, reset them to default, or contact your broadband provider for guidance rather than making sweeping changes.

How to stop a firewall from blocking the internet

Before making any changes, it’s important to say this upfront: don’t permanently disable your firewall – that’s like fixing a jammed door by removing it entirely.

Firewalls are there to protect you. The goal is to adjust them, not get rid of them. So:

1. Temporarily disable the firewall to test

As a first step, briefly turn the firewall off to check whether it’s actually the cause of the problem. If your internet access returns immediately, you’ve found your culprit.

The keyword here is temporarily. As soon as you’ve confirmed the firewall is involved, turn it straight back on. This test is just about diagnosis – not a long-term solution.

2. Add an exception (instead of opening everything up)

Once you know the firewall is blocking something, the safest fix is to allow only what you need.

Most firewalls let you add exceptions for:

• A specific app or program
• A web browser
• A service or port number
  

This means the firewall continues protecting you from everything else, while allowing the blocked traffic through. It’s the best balance between security and usability, and in most cases, it completely resolves the issue.

3. Reset firewall rules

Firewalls rely on sets of rules, and over time these can clash, duplicate, or become corrupted – especially after software updates, operating system upgrades, or installing new apps.

Resetting your firewall to its default settings clears out old or broken outbound rules and gives you a clean slate to work from. For many people, this instantly fixes unexplained blocking without needing any technical tweaking afterwards.

4. Update your software

Outdated security software is surprisingly good at causing false alarms.

Older firewall versions may:

• Misidentify safe traffic as dangerous
• Fail to recognise newer websites or apps
• Block connections that modern networks rely on
  

Make sure everything is up to date, including:

• Your operating system (Windows, macOS, etc.)
• Your router firmware
• Any antivirus or internet security software
  

Updates often improve compatibility and security, so this step can address multiple issues at once.

What if the firewall isn’t the problem?

If you’ve checked everything and your firewall seems to be behaving itself, don’t worry – there are a few other common causes that can look very similar.

Router or connection issues

Routers can quietly misbehave after running for long periods. A simple reboot refreshes the connection, clears temporary errors, and often restores normal service within minutes.

DNS problems

DNS issues make it look like the internet is down, even when your connection is fine. Websites fail to load because their names can’t be translated into IP addresses.

This can be fixed by:

• Restarting your router
• Switching to a public DNS provider
• Waiting for your ISP’s DNS to stabilise

WiFi interference or signal issues

WiFi interference is extremely common, and can cause slowdowns, dropouts, or failed connections that mimic firewall problems.

If some devices work while others don’t (or wired connections are fine but WiFi isn’t), interference is a likely culprit.

IP-related issues

Some websites and services rely on recognising your IP address. If it changes frequently, or if a service doesn’t trust it, you might experience connection problems.

If this sounds familiar, check out our article, Why has my IP address changed?

Firewalls are protectors, not enemies

A firewall blocking your internet can feel dramatic, but it’s usually just doing its job a little too enthusiastically.

With a few checks and tweaks, you can restore your connection without sacrificing network security. And if things still don’t add up, your broadband provider can help identify whether the issue is local, network-wide, or device-specific.

If you’re still dealing with unreliable connections, unexplained dropouts, or constant troubleshooting, it might not be your firewall at all – it could be the connection itself.

Our broadband packages are designed for stable, secure performance, with modern routers, expert support, and options to suit everything from busy households to home offices.

So if you want a connection that just works, explore our broadband packages and find what you need.