What is network segmentation
Network segmentation is the division of infrastructure into separate zones, between which traffic is controlled and restricted. Instead of one shared network where every device can see every other device, isolated segments are created - each with its own trust level and defined communication rules with the others.
In practice, this means that an employee's computer from the sales department does not have direct access to the finance server, an IP camera cannot communicate with workstations, and the guest network is completely isolated from company resources. Traffic between zones passes through a firewall, which decides what can pass and what cannot.
Why a flat network is a risk
In a flat network - that is, one without segmentation - every device has potential access to every other device. This is convenient from a management perspective, but catastrophic from a security standpoint.
When an attacker compromises one device - an employee's computer infected with malware, a printer with a default password, or an IP camera - they have an open path to the entire infrastructure. They can freely scan the network, look for servers with data, and try other devices. Nothing stops them, because there are no boundaries to cross.
Most ransomware attacks exploit exactly this property of flat networks. Malware that has reached one computer encrypts resources on all servers and workstations it has network access to within minutes. In a network without segmentation, that is often the entire company.
What segmentation looks like in practice
The basic division that is worth implementing in every company includes several zones. User network - employees' workstations and laptops. Server network - systems to which access should be strictly controlled. Device network - cameras, printers, IP phones, and other devices that do not need access to company resources. Guest network - isolated internet access without the ability to enter the internal network.
Each zone communicates with the others only to the extent necessary for operation. An employee can connect to a file server, but their computer has no reason to communicate with the camera in the reception area. A camera can send video to a recorder, but it does not have access to the user network.
Segmentation is closely linked to default passwords in network devices - even if an attacker compromises one device, segmentation limits the scope of that compromise to a single zone.
Segmentation and GDPR compliance
Network segmentation has a direct impact on personal data protection. GDPR requires the use of appropriate technical measures to ensure data security - and isolating systems that process personal data from the rest of the infrastructure is one such measure.
When a security incident occurs, segmentation also makes it possible to precisely determine which data may have been exposed. In a flat network, the answer to that question is simple and unpleasant - all of it.
What it looks like at Helpwise
Network segmentation is part of the standard infrastructure design we implement for our clients. We analyze which devices and systems are on the network, define zones and communication rules between them, configure VLANs and firewall rules. For existing environments, we perform an audit of the current network structure and implement segmentation in phases so as not to disrupt the company's day-to-day operations.