Network Segmentation 101: A Comprehensive Guide to Organizing and Protecting You

Digitizing a business is an increasingly common decision among entrepreneurs. Spurred by the recent need for businesses to operate online, it is also a much more efficient way of operating. That said, the digital world poses its own challenges and threats, with increasing concern regarding the issue of cybersecurity amidst greater cyber threats. Spending on cybersecurity is expected to increase to $10 billion by 2027 as more businesses struggle with the threat of a data breach.

This means that businesses are constantly on the lookout for new and innovative ways to protect their network, such as implementing Zero Trust policies in their security protocols. Firewalls, encryption, and the use of VPNs all add a layer of security to corporate networks. Network segmentation is another one of the ways in which a network can be protected from possible breaches and attacks.

What is Network Segmentation

In the simplest terms, network segmentation is a way of breaking up an enterprise network into smaller sections. This segregation technique reduces the vulnerability of the network in case of a potential attack, as it would be contained within one section of a wider network.

Breaking up a network into subnets allows each section to be monitored more closely and for traffic going in and out of the network to be vetted easily. Not only can it boost network performance and efficiency, but it also prevents network-wide outages from internal technical faults. Segmentation is a core concept of the Zero Trust policy, with corporations taking into consideration that sometimes insiders can act, purposely or accidentally, as nefarious agents.

Network segmentation can adopt one of two policies:

● Macro-segmentation: The network is broken up into multiple, larger segments which are monitored through internal firewalls.

● Micro-segmentation: Multiple segments are created from the larger sections, placing each device or application within its segment.

Micro-segmentation simply takes macro-segmentation one step further. Unlike with a macro setup, any traffic that is based between all applications in a single segment is also inspected. Its validity is verified before communication is established between applications.

How to Implement Network Segmentation

How you segment a certain network depends on the way it is configured. As each network is set up differently and serves different business needs, any segmentation you implement must take into account the unique architecture of the network. Common ways to segment include:

Physical segmentation

Physical segmentation is much like it sounds- the network is physically broken up into smaller segments. A physical and even a virtual firewall act as the protective barrier between the various sections. For simpler and smaller networks, this is a relatively easier way to segment a network, as it only requires a segregated architecture.

Logical segmentation

Logical segmentation is a virtual form of network segmentation. Rather than physical barriers between subnets, the network is separated into sections using virtual techniques. These include:

● Virtual Local Area Network (VLAN): VLAN tagging is used to automatically redirect any incoming traffic to the network to the appropriate subnet.

● Network addressing schemes: Network addresses are used based on which traffic is sent to the relevant subnet on the network

While VLAN is a much simpler approach to implement, network addressing schemes offer enhanced security by keeping internal addresses off the external network.

Best Practices in Network Segmentation

As far as security protocols go, segmentation is a great way to protect your network. When implementing a network segmentation solution, you want to ensure your approach is effective in building network security. Some tried and tested best practices in network segmentation include:

1. Implement least privilege

When you segment a network, you have to consider who should be allowed to access which subnets. Not every stakeholder needs untethered access to your entire corporate network. Not only should segmentation keep out unwanted external traffic, but it should also limit what internal traffic is acceptable for various subnets.

Zero Trust policies dictate that even internal users shouldn’t be automatically trusted and allowed access. This prevents users and subnets from ending up on a network subgroup they don’t need to perform their duties. Not only does this make it easier to monitor incoming and outgoing traffic, but it also reduces the likelihood of a breach.

2. Avoid over-segmentation

The principle behind network segmentation is not to just blindly create self-sufficient blocks of the corporate network. In fact, a series of well-researched and comprehensive policies dictate how you segment your network based on user accessibility and necessary functions. When you create too many segments, you make it that much harder to maintain the wider network.

Over-segmentation is one of the most common mistakes corporations tend to make, thinking that smaller subgroups will make the network more secure. However, unnecessary segments can interrupt traffic flow, slow down workflows, and create extra work in securing and managing additional and unnecessary segments. Instead, create workable principles and only segment where necessary.

3. Micro-segment to limit third-party access

Completely roping off third-party access to your network is unrealistic. Many businesses require third-party services and, as a result, must provide some network access for them to do their jobs. This does not just extend to suppliers and vendors- providing network access to customers and clients in the lobby has also become something of a necessity- but it requires the right safeguards to be put in place.

When implementing network segmentation, businesses often overlook limiting remote access for third parties. They can be a major risk for attacks and vulnerabilities, and it is important to incorporate remote data safety protocals into your network segmentation policy. Just as with internal users, third parties should not be able to access any more of the corporate network than they need to.

4. Combine similar network resources

This is a pretty basic principle in network segmentation, but it still needs to be said. When segmenting, your policy should focus on grouping similar resources together. The best way to do this, in terms of security, is to group networks by levels of data sensitivity.

Subnets with highly sensitive data can be grouped together, where additional levels of protection and security can be added without too much hassle. Subnets lower on the sensitivity scale can be similarly bunched together with less severe security protocols in place.

Wrapping Up

As far as cybersecurity goes, network segmentation is a relatively simple way to ensure unwanted parties do not gain access to your network. In the event that does happen, segmentation limits exposure and, as a result, prevents greater degrees of data loss or theft.

Implementing segmentation is a matter of well-developed principles that take into account the unique architecture of the corporate network, as well as the data security needs of the organization as a whole.