Lesson 4.5 — Software firewalls on laptops, desktops and remote-worker devices

This lesson helps the learner understand and evidence software firewalls on in-scope devices.

What You'll Be Able to Do

By the end of this lesson, you will be able to:

identify which in-scope devices require software firewall protection
confirm whether software firewalls are enabled and managed
collect appropriate evidence
record any gaps before moving into secure configuration and update management.

Why This Matters

It explains when software firewalls are needed, why they are especially important for remote workers and devices used on untrusted networks, how to check common operating systems, and how to avoid confusing software firewalls with network boundary firewalls.

The most common problems are:

assuming the office firewall protects laptops when they are used remotely;
checking only Windows devices and forgetting Macs or Linux devices;
forgetting remote-worker laptops;
forgetting contractor or BYOD devices;

The Core Rule

A software firewall protects an individual device.

It is especially important for laptops, desktops and other devices used away from the office or on untrusted networks such as home Wi-Fi, public Wi-Fi, hotels, client sites and shared workspaces.

What the CE Assessor Looks For

A strong position shows:

all in-scope laptops and desktops have software firewalls enabled;
remote-worker devices are included;
public/untrusted network profiles are protected;
users cannot disable the firewall without permission;
exceptions are controlled and reviewed;
server host firewall approach is understood;

Common Mistakes

assuming the office firewall protects laptops when they are used remotely;
checking only Windows devices and forgetting Macs or Linux devices;
forgetting remote-worker laptops;
forgetting contractor or BYOD devices;
assuming mobile devices use the same firewall model as laptops;
treating software firewalls as partial-scope boundaries;

Copy This

Work through the workbook activity for this lesson. Each question maps directly to the CE questionnaire.

Quick Checklist

Before moving on, make sure you can say yes to these:

[ ] What is a software firewall?
[ ] Why are software firewalls especially important for remote workers?
[ ] Does the office boundary firewall protect a laptop when it is used on public Wi-Fi?
[ ] Can software firewalls define the boundary of a partial Cyber Essentials scope?
[ ] What should be checked on Windows devices?

Your Action

Do this now — it takes 10–20 minutes.

Check that the software firewall is enabled on at least one device from each operating system type you use. Record the outcome in Section F.

Key Takeaway

Software firewall evidence should match the device groups in scope, including Windows, macOS, Linux, servers, remote workers and any BYOD or contractor devices where relevant.

Your Workbook Activity

Complete: Software firewall device control record

Next Lesson

In the next lesson: Firewall evidence, common failures and final A4 answer review