Network Segmentation best practices & implementation

Growing a business also means expanding its IT infrastructure. At some point, it can become too big, which brings the necessity to break it up into smaller chunks that would be more manageable. Such network segmentation helps to create boundaries between data flows and limits the scope of potential cyber-attacks.

That said, network segmentation takes a long time and requires in-depth strategic planning. To help you navigate this IT transition, we present the best practices for effective network segmentation.

Network segmentation best practices

Network segmentation serves as both network security practice and defensive cybersecurity strategy. Splitting the internal network into smaller network segments allows administrators to adapt security levels. Depending on your risk model, you can adjust your plan for maximum effectiveness. That way, sensitive resources could be protected without interfering with regular employees' work functions.

The solution also limits lateral movement for hackers. They become sealed off in isolated network segment instances. Smaller subsegments also shrink the attack surface and help implement security frameworks like Zero Trust.

Here are some of the best practices when implementing network segmentation.

Avoid under or over-segmentation

One of the common mistakes is splitting the network into too many or too few subsegments. Both approaches are excesses in different areas, each detrimental to your organization's security.

Segmenting your network into too small segments creates an illusion that the control over the network can be that precise. However, the reality is that over-segmentation brings you back to square one. This creates an overabundance of network segments defeating the purpose for what the segmentation was intended in the first place.

Under-segmenting can also be harmful if there isn't enough separation between each network. Likely, the hackers could use overlaps between large network segments to escalate their access privileges.

Segmentation should balance to ensure the best conditions for monitoring and applying security policies. In all cases, network security should align with your broader cybersecurity goals.

Continuous audits and monitoring

Every network segmentation process should go through a comprehensive evaluation to ensure there are no flaws in the setup. Penetration tests and auditing are valuable here to be 100% sure that there are no gaps in the system. Your security should always be airtight.

This is further complicated by the fact that networks are never static. The number of connected devices constantly shifts as users join and leave the network. The best way to capture the pulse of this new system is to perform periodic audits. This should give a detailed picture of various weak spots threatening the network.

Restrict third-party access

While third-party partners bring value to the company, they should also be treated as liabilities. Rarely if ever, a third-party provider needs full network access to your internal systems. In cases when a partner gets breached, the hackers can take out the two targets simultaneously.

Therefore, partners should be treated as separate entities and allowed into internal networks with restrictions. Limiting their access to allow only work functions doesn't harm their performance. Yet, this significantly contributes to the enterprise's security.

Consolidate network resources

Combining similar network resources will make it much easier to protect them. Low-sensitivity resources should be grouped with low-sensitivity resources. Yet, most sensitive data should be kept with resources of similar importance. This allows tighter security controls in the most important areas while giving some flexibility.

Such an approach positively translates into network performance, as well. Without unnecessary obstacles for low–risk work resources, employees aren’t interrupted for authentication checks. This allows focusing on the security suite where it would be the most useful.

Network segmentation implementation strategies

Successful implementation of network segmentation requires clear guidelines. Here are some examples that could help you finalize your network segmentation implementation strategy.

Clear vision

One of the best tips for network segmentation is critically examining the company's current situation. What security risks does the enterprise face, what could be improved, and where does network segmentation fit in this whole picture.

Your goal should be to identify existing gaps using network segmentation as a solution to them rather than segmenting the network just for the sake of it. You shouldn't overlook existing processes and evaluate whether changes could interfere with them. Mind that the best implementation of network segmentation is those that act as a supplement rather than a substitute.

Evaluate resources and capabilities

Auditing your infrastructure is one of the necessary steps of preparation, including various sub-sections like virtual local area networks. The findings in this stage can significantly affect your transition planning. This also serves as a guideline for how many network segments you should have. The number of critical resources that have to be protected will directly shape the complete outlook of your plan.

The results of the audit can also help with identifying particular types of security risks that your company is facing. If the company's network predominantly relies on a specific device + OS combination or if there are a lot of IoT devices, this should also figure in your strategy.

Consider cross-organizational dependencies

Changes in such areas as the network could send shockwaves throughout the whole system. This is especially the case if your company is bigger, which is further complicated by having third-party partners. This means taking a firm stance on which organization's areas should be connected, which network traffic needs segmentation and its strictness.

All of these questions should be decided before any action is taken. It's also never a bad idea to listen to the third parties needs to ensure that their operations aren't disrupted. The same applies to your internal operations as well, especially in departments where the level of collaboration is very high.

Segment your action roadmap

Network segmentation implementation is a colossal project, so it's much easier to plan it as a multi-step process rather than a one-time move. Gradual transition gives you more time to iron out shortcomings of the setup. Smaller-scale implementation gives you insights that will be useful on a bigger scale.

Knowing which components work well can give you enough time to refine the strategy. This benefits the company, as various errors could be identified earlier. In turn, this doesn't threaten the most important company resources.

Start implementing

After the strategy is complete, the implementation phase should follow. Security, routes, zones, and policies must be created following the network segmentation strategy. What is important in this step is documentation. A detailed description of how segmentation was implemented can be invaluable during audits. It can also be very useful if something goes wrong, and you must trace your steps to find the culprit.

Finally, this makes sense from an administrative standpoint. This would minimize the threat you could be facing from employee changes. Documentation could help them get up to speed when making adjustments.

Conclusion

In most cases, network segmentation is a vital step for organizations trying to improve their cybersecurity. When implemented, it can minimize various security risks that threaten the organization's sensitive data security. However, it's important to take a careful approach when reforming the whole structure.

Segmented networks should keep a healthy balance between being under or over-segmented. Meanwhile, the whole process requires monitoring and analysis. You must figure out which resources should be grouped and what access rules apply to third-party providers.

The bottom line is that while network segmentation can be a colossal task, it's effective at stopping cyber attacks in their tracks. Which is something that can be worth the struggle.