A network can look perfectly normal while a former employee still has access, a critical server has missed months of updates, or guest Wi-Fi sits too close to business systems. Knowing how to audit network security gives your business a clear picture of these risks before they become downtime, data loss or a costly cyber incident.
For small and medium businesses, an audit does not need to mean pulling everything apart or disrupting a busy workday. It is a structured review of who and what can access your systems, how information moves through the business, and whether the safeguards you rely on will work when needed. The goal is practical: identify the gaps, prioritise the ones that matter most, and create a realistic plan to fix them.
Start with a clear audit scope
Trying to review every system, setting and historical record at once can turn a security audit into a project that never finishes. Begin by defining what is in scope. For many businesses, that means internet connections, firewalls, switches, Wi-Fi, computers, mobiles, servers, cloud platforms, phone systems and backup services.
Also consider the systems that often sit outside the usual IT conversation. CCTV recorders, access control, smart displays, point-of-sale devices, printers and office automation equipment are all connected assets. If they are reachable on the network, they need to be accounted for.
The appropriate scope depends on your operation. A professional office with cloud-based applications may focus heavily on identity, Microsoft 365 settings and mobile devices. A warehouse, retail site or multi-location business may also need to examine site-to-site connectivity, operational equipment, guest access and physical-security systems. Write down the locations, systems and business processes that the audit must cover before technical checks begin.
Build an accurate asset and network inventory
You cannot secure equipment you do not know exists. Create an inventory of every device connected to the network, including its owner, location, operating system, function, IP address and whether it is managed by the business.
This process regularly uncovers forgotten equipment: an old laptop in a drawer, a personal mobile with company email, a retired server still running, or a network camera using default credentials. These devices can become an easy entry point because they are rarely patched, monitored or reviewed.
Next, map how the network is arranged. Identify the internet connection, firewall, switches, wireless access points, servers, cloud services and remote connections. Record which systems can communicate with each other. A flat network, where every device can reach every other device, may be simple to operate but increases the damage a compromised machine can cause.
Segmentation is often a sensible improvement. Guest Wi-Fi should be separate from staff devices, while CCTV, alarms, printers and other specialist equipment may need their own controlled network areas. The right design depends on the equipment and the way your staff work, but separation reduces unnecessary exposure.
Review users, accounts and access rights
User access is one of the most important parts of any network security audit. Start with a list of all accounts across your key systems: network logins, email, cloud storage, accounting software, remote-access tools, administrator accounts and business applications.
Check that each account belongs to an active person or approved service. Remove accounts for former employees, contractors and suppliers who no longer require access. Shared logins should be replaced where possible, because they make accountability difficult and passwords tend to be shared too widely.
Then review permissions. Staff should have the access required for their role, not unrestricted access simply because it is convenient. Administrative privileges deserve particular attention. A user with local administrator rights can install software, alter security settings or accidentally expose the device to greater risk.
Multi-factor authentication should protect email, cloud platforms, remote access and any system containing sensitive information. Password policies still matter, but a strong password on its own is no longer enough protection against phishing, password reuse or stolen credentials.
Check firewall, Wi-Fi and remote access settings
The firewall is the gatekeeper between your network and the internet. Review its configuration for old rules, unnecessary open ports, remote-management settings and services that are exposed publicly. Rules added for a one-off project can remain in place for years unless someone reviews them deliberately.
Remote access deserves the same scrutiny. Confirm which staff, suppliers and support providers can connect from outside the office, how they authenticate and whether their access is still required. Remote desktop services should not be exposed directly to the internet without appropriate protection. A properly configured virtual private network, strong authentication and access logging are usually safer options.
For Wi-Fi, check that business, guest and device networks are separate. Confirm the wireless encryption is current, the administrator password has been changed from the default, and access-point firmware is supported and updated. Guest Wi-Fi should provide internet access without allowing guests to browse staff computers, servers or security devices.
Assess patching, endpoint protection and monitoring
A network audit should establish whether every supported device receives operating system and application updates within a reasonable timeframe. This includes laptops that spend most of their time away from the office. Unpatched browsers, remote-support tools, routers and firewall firmware can be just as significant as unpatched Windows devices.
Check endpoint protection on workstations and servers. Confirm it is installed, current and centrally visible, rather than assuming each device is protected because it was set up that way originally. Look for machines that have stopped reporting, have protection disabled or are running an unsupported operating system.
Monitoring is where an audit moves beyond a one-time checklist. Review what alerts are generated for failed logins, suspicious activity, offline devices, low storage, backup failures and firewall events. Too many alerts can be as unhelpful as none if nobody has a clear responsibility to investigate them. The useful question is not just whether monitoring exists, but what happens when it identifies a problem.
Test backup and recovery, not just backup status
A green tick beside a backup job does not prove the business can recover from ransomware, hardware failure or accidental deletion. Review what data is backed up, how often it runs, where copies are stored and how long they are retained.
There should be an offsite or cloud-based copy that cannot be easily altered by an attacker who gains access to the main network. For critical systems, consider whether backups are protected from deletion through separate credentials, immutability or another controlled method.
Most importantly, test a restoration. Recover a sample file, mailbox or server workload into a safe location and measure how long it takes. A business that needs systems restored within hours needs a different backup and disaster-recovery arrangement from one that can tolerate a day or two of disruption. Recovery objectives should reflect commercial reality, not an assumption made years ago.
Look for vulnerabilities and verify the findings
Vulnerability scanning can identify missing patches, weak encryption, exposed services and insecure configurations across the environment. It is useful, but it should not be treated as the final answer. Scanners can report findings that are not relevant to your setup, while a poorly configured cloud service or excessive user permission may not be obvious from a technical scan alone.
Use scan results alongside configuration reviews, account checks and discussions with the people who use the systems every day. Penetration testing may be appropriate where you handle sensitive data, need to meet contractual obligations, or want to understand how a real attacker could move through the environment. It should be carefully scoped so testing does not interrupt critical operations.
Turn the audit into an action plan
An audit report is only useful if it leads to action. Rank findings by the likelihood of an issue occurring and the impact it would have on the business. An exposed remote-access service, unsupported server or no working backup should be dealt with quickly. Minor configuration improvements can be scheduled into routine maintenance.
For each action, assign an owner, target date and expected outcome. Avoid vague recommendations such as “improve security”. A useful action is specific: enable multi-factor authentication for all Microsoft 365 accounts, isolate guest Wi-Fi, remove inactive accounts, or test server recovery quarterly.
EHW Technology approaches audits as a practical business exercise, connecting technical findings with the systems your staff rely on to communicate, serve customers and keep operating. The best result is not a lengthy document full of jargon. It is a prioritised security plan that fits your budget, risk level and operational needs.
Network security is not a once-only project. Review access when people change roles, reassess the network when new technology is added, and test recovery before an emergency forces the issue. A good audit leaves your business with fewer unknowns and clearer decisions about what to protect next.