10 Ways to Make Your Business Network More Secure in 2026

Your business network connects almost everything your organisation depends on.

Computers, servers, printers, Wi-Fi, CCTV, phones, cloud services, Microsoft 365, access-control systems and remote workers may all rely on it.

That makes the network an attractive target.

If an attacker compromises one poorly protected device and your network is flat and unrestricted, they may be able to move from that device towards much more valuable systems.

The good news is that improving network security does not necessarily require rebuilding everything from scratch.

Here are 10 practical ways to make your business network more secure in 2026.

1. Use a Proper Business Firewall

Your firewall sits between your internal network and external networks such as the internet.

But simply having a firewall is not enough.

It needs to be:

• correctly configured
• regularly updated
• actively supported by the manufacturer
• monitored
• backed up
• reviewed periodically

Old rules should also be removed.

A firewall installed five years ago may contain rules nobody remembers creating, services that are no longer required or ports that were temporarily opened and never closed.

Businesses should periodically review:

• inbound rules
• outbound rules
• port forwarding
• VPN access
• administrator accounts
• firmware versions
• security subscriptions
• configuration backups

And avoid exposing services directly to the internet unless there is a genuine requirement.

The NCSC recommends controlling access at network boundaries and keeping network infrastructure properly maintained as part of fundamental network security.

2. Segment Your Network

One of the biggest mistakes businesses make is creating one enormous network where everything can communicate with everything else.

Imagine an employee laptop, CCTV camera, printer, server and guest Wi-Fi user all effectively sitting on the same unrestricted network.

If one device is compromised, an attacker may have far more opportunities to move around.

Network segmentation divides the environment into smaller security zones.

For example, you might separate:

• employee computers
• servers
• guest Wi-Fi
• VoIP phones
• CCTV
• building-management systems
• printers
• IoT devices
• management interfaces

Firewall rules or other security controls then determine what communication is permitted between them.

Your CCTV cameras probably do not need unrestricted access to your finance server.

Your guest Wi-Fi certainly should not.

The NCSC describes segmentation as an important way to control traffic and reduce the impact of a compromise. Its latest ZTNA guidance also describes large, flat networks without segmentation as an architectural anti-pattern.

3. Secure Your Business Wi-Fi Properly

Business Wi-Fi deserves the same attention as the wired network.

Use modern, supported wireless equipment and appropriate encryption.

Businesses should also separate corporate and guest access.

Your guest network should provide visitors with internet connectivity without giving them access to internal business resources.

Depending on the organisation, it may also make sense to create separate wireless networks for:

• employees
• visitors
• IoT devices
• CCTV
• specialist equipment

Avoid leaving default administrator credentials in place.

Management interfaces should only be accessible to authorised administrators, and wireless access points should receive firmware updates just like computers and servers.

4. Keep Every Network Device Updated

Most businesses understand that Windows needs security updates.

They sometimes forget that network infrastructure needs them too.

That includes:

• firewalls
• routers
• switches
• wireless access points
• VPN appliances
• NAS devices
• CCTV systems
• printers
• VoIP equipment

These devices run software and firmware.

Software can contain vulnerabilities.

The NCSC specifically includes updating systems and network components among its fundamental network-security practices.

You should therefore know:

What network equipment do we have, what firmware is it running, and is the manufacturer still supporting it?

If you cannot answer those questions, start with an asset inventory.

Unsupported infrastructure should have a replacement plan.

5. Protect Administrator Accounts

Network infrastructure often has extremely powerful administrator accounts.

If one of those accounts is compromised, an attacker could potentially change firewall rules, create VPN users, alter DNS settings or disable security controls.

Protect administrative access carefully.

Use:

• unique administrator accounts
• strong passwords
• MFA where supported
• separate day-to-day and administrative accounts
• restricted management access
• centralised logging where practical

Avoid using one shared admin account across every network device.

That makes accountability difficult and increases the damage caused if the credentials are exposed.

The principle should be simple:

Nobody should have administrative access unless they genuinely need it.

6. Stop Treating a VPN as Automatic Trust

VPNs remain useful.

They can provide secure remote access to internal systems.

But there is an important distinction:

A VPN creates a protected connection. It should not automatically mean the user can access everything on the network.

Traditional VPN designs sometimes effectively say:

You successfully connected to the VPN, therefore you are now inside the trusted network.

That model is becoming increasingly unsuitable for modern environments.

The NCSC's new Zero Trust Network Access guidance says users and devices should not gain access simply because they are connected to a corporate network, using a VPN or connecting from a familiar location. Access should instead be explicitly authorised according to policy.

At a minimum, remote access should use:

• MFA
• individual accounts
• restricted permissions
• secure devices
• logging
• appropriate segmentation

Businesses should also consider whether Zero Trust Network Access (ZTNA) would be more appropriate for some applications.

7. Consider Zero Trust Network Access

ZTNA changes the question from:

“Can this user connect to our network?”

to:

“Should this user, on this device, under these circumstances, be allowed to access this particular application?”

That is an important difference.

The NCSC's May 2026 ZTNA guidance says access should be explicitly authorised using defined policies and contextual information rather than relying on network location alone.

Signals can include:

• user identity
• device identity
• device health
• user behaviour
• application sensitivity

A user might therefore be allowed access to one business application without receiving broad access to the entire internal network.

ZTNA is not automatically better simply because a product has “Zero Trust” written on the box.

The architecture matters.

The NCSC specifically warns against ZTNA implementations that simply reproduce the old model by allowing broad network access after authentication.

For some SMEs, a traditional well-secured VPN remains perfectly appropriate.

For others, particularly those with extensive hybrid working and cloud applications, ZTNA may offer more granular control.

8. Control What Devices Can Connect

Do you actually know what is connected to your network?

You may have more devices than you think.

Alongside laptops and desktops there may be:

• mobile phones
• tablets
• smart TVs
• CCTV cameras
• door-entry systems
• printers
• meeting-room equipment
• IoT devices
• employee-owned devices
• old hardware nobody remembers installing

Every connected device increases the potential attack surface.

Maintain an inventory and identify unfamiliar equipment.

Where possible, business devices should be centrally managed.

Microsoft Intune or another device-management platform can help enforce requirements such as encryption, supported operating systems, endpoint protection and security configuration.

Modern Zero Trust approaches increasingly consider device identity and device health alongside the user's identity when deciding whether access should be granted.

9. Monitor the Network

Security monitoring is not just for huge enterprises.

Useful network monitoring can help identify:

• unexpected devices
• repeated failed logins
• unusual outbound traffic
• unexpected connections
• firewall configuration changes
• VPN activity
• bandwidth anomalies
• network failures
• suspicious behaviour

But there is a crucial point:

Collecting logs is not the same as monitoring them.

A firewall can generate thousands of alerts.

If nobody reviews them, investigates suspicious activity or responds when something important happens, the alerts provide limited protection.

Where appropriate, logs should be centralised so activity across different systems can be correlated.

Observability is also one of the NCSC's eight key requirements for modern ZTNA architectures.

The objective is not to watch every packet manually.

It is to make sure meaningful security events are visible and actionable.

10. Design for a Breach, Not Just Prevention

No network can be guaranteed never to be compromised.

That means your design should answer another question:

What happens if an attacker gets in?

A well-designed environment should make it difficult for them to move further.

That is where several of the controls in this article come together:

• segmentation
• least privilege
• MFA
• endpoint protection
• secure administrator accounts
• monitoring
• controlled remote access
• patching
• protected backups

The NCSC's Zero Trust guidance deliberately treats networks themselves as potentially hostile rather than assuming an internal network is inherently safe.

That does not mean traditional network security is irrelevant.

It means being connected to the office LAN should no longer automatically grant trust.

What About Cloud Services?

Businesses increasingly use Microsoft 365, Azure and other SaaS applications that may not sit on the traditional office network at all.

Network security therefore needs to work alongside:

• identity security
• Conditional Access
• MFA
• endpoint management
• data protection
• cloud security
• email security

The traditional idea of building a strong perimeter around an office is no longer enough when employees can access company information from laptops, homes, mobile devices and cloud applications.

This is one of the main reasons Zero Trust has become so important.

A Quick Network Security Checklist

Ask your IT provider these questions:

1. Is our firewall fully supported and patched?
2. When were our firewall rules last reviewed?
3. Is our network segmented?
4. Is guest Wi-Fi completely isolated?
5. Are our switches and access points supported?
6. Does all remote access require MFA?
7. Does our VPN provide more access than users actually need?
8. Do we know every device connected to our network?
9. Are network security logs actively monitored?
10. What prevents an attacker moving between systems if one device is compromised?

If several answers are “I don't know”, your network probably deserves a review.

Security Is About Layers

There is no single product that makes a network secure.

A firewall can fail.

A password can be stolen.

A laptop can be compromised.

An employee can click a phishing link.

A vulnerability can be discovered before a patch is available.

Strong security therefore relies on multiple layers.

If one control fails, another should reduce the attacker's options.

For example:

Phishing succeeds → MFA helps protect the account → device controls restrict access → segmentation limits movement → monitoring detects unusual behaviour → backups support recovery.

That is a much stronger strategy than relying on one expensive firewall at the edge of the network.

How Hamilton Group Can Help

Hamilton Group can review your existing network and identify weaknesses before they become outages or security incidents.

We can help with:

• business firewalls
• network segmentation
• managed switches
• business Wi-Fi
• secure remote access
• VPNs
• Zero Trust and ZTNA planning
• Microsoft Entra ID
• Conditional Access
• Microsoft Intune
• network monitoring
• firmware and patch management
• cybersecurity
• backup and business continuity
• network upgrades and replacements

The objective is not simply to install more security products.

It is to design an environment where users can access what they need while unnecessary access is restricted and suspicious activity can be detected quickly.

Visit or call 0330 043 0069 to discuss a network and cybersecurity review.