Network Penetration Testing · United Kingdom
Network penetration testing that tests the wire, not the diagram.
Your network diagram shows neat boundaries between the office, the servers and the guest wireless. We test whether those boundaries exist in the traffic. In most UK engagements, at least one of them does not.
CREST-certified operators · perimeter, internal, segmentation and wireless · every finding human-verified
What is network penetration testing?
Network penetration testing is an authorised attack on the network layer itself: the routes, boundaries and controls that decide which system can talk to which. A tester proves which paths through your network are actually open, rather than which ones your documentation says should be.
It covers both directions. From outside, the test measures what your perimeter exposes and what gets through your firewall. From inside, it measures whether your segmentation holds when somebody with a laptop tries to cross it.
Segmentation is where this test earns its cost. Firms build a flat network for good operational reasons, then add VLANs and firewall rules over years, and nobody ever verifies the result end to end. We do, and we hand you the rule that needs changing.
What we attack
Perimeter, internal, segmentation, wireless
Scope the whole network or just the boundary you are worried about.
| Surface | What we look for |
|---|---|
| Perimeter and firewall | Which ports and protocols actually pass, which rules have quietly become permissive, and which edge devices run exploited versions. |
| Segmentation testing | Whether your user network reaches your server network, your card environment, your operational technology and your backups. We test every boundary you claim to enforce. |
| Network protocols | LLMNR, NBT-NS and mDNS poisoning, SMB relay, IPv6 takeover and the other default behaviours that hand an attacker credentials without a single exploit. |
| Wireless | Corporate and guest wireless separation, weak pre-shared keys, rogue access point susceptibility and whether the guest network truly cannot see the corporate one. |
| Network devices | Switches, routers, load balancers and management interfaces. Default credentials on a switch management VLAN remain one of the most common findings in UK estates. |
| Remote access | VPN configuration, split tunnelling, and whether a compromised home device reaches more of your network than it should. |
What you get
The routes that are actually open
Every assessment starts where an attacker would: outside, watching, looking for the one door left ajar. We find it, then we show you the walk-through.
- A segmentation matrix: every boundary tested, and whether it held
- The specific firewall and switch rules that need changing, by name
- Proof of exploit for each finding, with the traffic that worked
- Findings ranked by what each open route reaches
- Verified by a CREST-certified operator before it reaches you
- A year of unlimited re-tests through RTP Robin as your network changes
Before you ask
Network penetration testing, answered
Every assessment starts where an attacker would: outside, watching, looking for the one door left ajar. We find it, then we show you the walk-through.
What is network penetration testing?
Network penetration testing is an authorised attack on your network infrastructure and the boundaries within it. A tester probes your perimeter, your internal network, your segmentation and your wireless, and proves which routes between systems are genuinely open. It answers a question no configuration review can: does the traffic actually behave the way your firewall rules and network diagram say it should?
What does a network penetration test include?
A full network penetration test covers the perimeter and firewall, internal network protocols and privilege paths, segmentation between every zone you claim to separate, wireless networks including guest separation, network device configuration, and remote access. Most UK organisations scope external and segmentation first, because those two produce the findings that change architecture decisions rather than patch schedules.
How is network penetration testing different from infrastructure penetration testing?
Network testing examines the routes between systems: firewalls, VLANs, segmentation, protocols and wireless. Infrastructure testing examines the systems themselves: servers, Active Directory, hypervisors, patching and backups. They overlap at the edges and are often bought together, but the findings are different in kind. Network testing tells you that your user network can reach your backup server. Infrastructure testing tells you that the backup server has an unpatched service and a weak service account.
Will testing our network cause an outage?
No. We agree the rules before we start, including which systems are fragile and what we never touch. Denial-of-service testing is excluded by default and only ever run on explicit request against systems you nominate, at a time you choose. Everything else runs at a pace and volume that your network handles normally, and we stay in contact with your team throughout.
Go deeper
Find out which of your network boundaries is fiction.
Get a free audit