Business firewalls: what they do and when you need one

What it does

• Filters traffic between the internet and the network, and between internal networks.
• Separates: office, guests, cameras, telephony and connected devices, each with its own rules.
• Provides secure remote access through a VPN.
• Manages several internet connections and fails over to the backup if the main one drops.
• Logs what happens, so an incident can be investigated.

How it differs from the operator's router

The operator's router includes a basic firewall that blocks incoming connections. It usually doesn't allow rules between internal networks, professional VPN, fine-grained prioritisation or useful logging. For a home it's enough; for a business with several networks, it falls short.

Features that matter for a small business

• VLANs and rules between them: guest WiFi must not reach the till.
• VPN for remote work and for linking sites.
• Dual connection with automatic failover.
• Prioritisation of voice and critical applications.
• Threat filtering: blocking malicious domains and intrusion detection, depending on the device.
• Security updates for years.

Rules: deny by default

Best practice is to block everything and open only what's needed. Opening ports to a camera recorder, a NAS or remote desktop is behind many incidents: that's what the VPN is for.

Maintenance

• Up-to-date firmware.
• Regular rule reviews: anything no longer used is removed.
• A backup of the configuration.
• Strong admin passwords with two-factor authentication.

When you need one

• There's more than one network: staff, guests, cameras.
• Someone connects from outside.
• Customer data or payments are handled.
• The connection is critical and needs a backup.

And when you don't

In a home with no remote access or separate networks, the operator's router with a sound configuration is usually enough. The key is not to open ports and to keep it updated.