Signs Your Business Firewall Is Due for Replacement

The clearest signs your business firewall is due for replacement are that it no longer receives firmware updates, it slows your internet down when security features are on, or it lacks modern protections like a built-in zero trust gateway. An appliance past its end-of-life date is the most urgent case, because it stops getting security patches and becomes a liability rather than a protection. If your firewall is more than about five years old, it is worth a hard look regardless of whether it still appears to work.

Key facts

• A firewall past its end-of-life date no longer receives security patches or firmware updates and should be replaced as a priority.
• Most business firewall appliances have a useful life of around three to five years before performance and support become issues.
• An underpowered firewall slows internet throughput once features like encrypted traffic inspection are enabled.
• Older appliances often lack modern capabilities such as a built-in zero trust network access gateway and SD-WAN failover.
• The upfront cost of replacement is the most common reason firewall upgrades get deferred, which Firewall as a Service removes.

How do you know when a firewall is past its end of life?

A firewall is past its end of life when the vendor stops issuing firmware and security updates for that model, which is published as an end-of-life or end-of-support date. After that date the appliance keeps running but stops getting patched, so any newly discovered vulnerability in it stays open. This is the single most important signal, because a firewall is a security device sitting at the edge of your network, and an unpatched one is worse than useless. It is an advertised way in.

Check your model's end-of-support date against the vendor's lifecycle page, or ask whoever manages it. If that date has passed, or is within the next year, replacement should be on the table now rather than later. (We have walked into more than one Sydney SME running a firewall that went end-of-support years earlier, still humming away, still wide open.)

Why is your firewall slowing down the internet?

A firewall slows your internet when the appliance is too small for your connection speed and the security features you have enabled. Modern protection like intrusion prevention and encrypted traffic inspection is processing-heavy, and inspecting encrypted traffic in particular can cut an underpowered appliance's throughput dramatically. If you upgraded your internet plan but kept the same firewall, or you turned on more security features over time, you can end up paying for fast fibre and only seeing a fraction of it.

The tell is a firewall that copes fine with the features switched off but chokes when they are on. That is not a reason to turn the features off, which some businesses quietly do. It is a sign the appliance is undersized for the job and needs stepping up.

What modern features is an old firewall missing?

Older firewalls typically lack a built-in zero trust network access gateway, integrated SD-WAN, and the tight endpoint integration that current appliances use to isolate compromised devices automatically. A zero trust gateway lets remote staff reach specific internal applications without a traditional VPN that exposes the whole network, which matters far more now that hybrid work is normal. SD-WAN manages multiple internet links with automatic failover, so a single line dropping does not take you offline.

If your remote access still runs on an old-style VPN and a single internet outage still means the office goes dark, your firewall is a generation or two behind what is available. Those are not luxury features anymore. They are the baseline for a business that has staff working from anywhere.

What does it cost to replace a firewall?

Replacing a firewall traditionally means an upfront capital cost for the appliance plus a multi-year security subscription, which is exactly the cost that makes businesses defer the upgrade. That deferral is the real risk, because the longer an end-of-life appliance stays in place, the longer the network sits exposed. The technology decision is usually easy. The budget decision is what stalls.

This is where Firewall as a Service changes the maths. Instead of a lump-sum purchase, you take the replacement appliance on a monthly fee that includes the hardware, the security subscription, and management, with no upfront cost. For a business that has been putting off a firewall refresh because of the price tag, it removes the one obstacle that was actually in the way. We cover this fully on our Sophos Firewall page and our Firewall as a Service page. The old appliance gets replaced, the network gets current protection, and the cost becomes a predictable monthly line rather than a capital hit.

Frequently asked questions

How often should a business firewall be replaced?

Most business firewall appliances should be reviewed at around three to five years, and replaced once they reach end of support or can no longer handle your internet speed with security features on. The vendor's end-of-support date is the hard deadline, because after it the appliance stops receiving security patches.

Is it safe to keep using a firewall past its end-of-life date?

No. Once a firewall passes end of support it stops getting firmware and security updates, so any new vulnerability in it stays unpatched. Because the firewall sits at the edge of your network, an unpatched one is a direct route in for attackers and should be replaced as a priority.

Why does my internet slow down with the firewall on?

Because the appliance is undersized for your connection speed and the security features enabled. Intrusion prevention and encrypted traffic inspection are processing-heavy, and an underpowered firewall cannot inspect at full line speed, so throughput drops. The fix is a firewall sized correctly for your traffic, not turning the protection off.

Can I replace a firewall without a big upfront cost?

Yes. Firewall as a Service lets you take a replacement appliance on a monthly fee that includes the hardware, the security subscription, and management, with no upfront purchase. It is a common way to refresh an ageing firewall without a capital project stalling the decision.

If your firewall is getting on in years, or you are not sure when it last had a firmware update, we can check its status and size a replacement without the upfront cost. Call 4iT on 1800 367 448, or read how we deliver Firewall as a Service.