Firewall
A software or hardware component that filters network traffic by defined rules and blocks unauthorized access.
A firewall filters network traffic by defined rules and blocks unauthorized access. Windows and macOS ship with a software firewall; routers include a hardware firewall.
Modern antivirus suites like Norton 360 or Bitdefender Total Security extend the default firewall with extra rules and behavioural analysis.
Why this matters in 2026
The Windows 11 software firewall is active by default in 2026 and reliably blocks inbound connections. The interesting part is outbound. The default Defender firewall does not block outbound connections from suspicious processes – that is a killer feature of premium suites from Bitdefender, Norton and Kaspersky.
How to protect yourself
Leave the built-in firewall in Windows/macOS at defaults – it is solidly configured. For more control, install a suite with an outbound firewall (Bitdefender, Norton, Kaspersky). On the router: disable UPnP, change the default password, enable the guest Wi-Fi (isolates IoT devices from your main network).