Microsegmentation with Fortinet Firewalls — Securing Servers

Quick Take

• Microsegmentation is essential for modern server security.
• It isolates threats; if one segment is compromised, the whole network isn’t.
• This implementation can be rendered both scalable and efficient by using Fortinet’s firewall solutions.
• This approach, often used for banks, greatly reduces attack surfaces.
• If you haven’t been doing this for your servers yet, you need to.

What is Microsegmentation?

Let’s begin with the basics — because frankly, this buzzword has been thrown around quite a bit, and not everyone seems to grasp it.

Microsegmentation involves building super secure areas within your larger environment. Rather than giving each server free run of the place, each server or application gets slotted into its own micro-zone, hardcore zoned in.

Think of your network as an old-school office building. If the front door was wide open, it meant that once someone got in, they had access to every room. Now think of a building where every office had a different keycard — breaking into one office doesn’t allow free access to the whole building. That’s microsegmentation in a nutshell.

How It Protects Servers

In the early 2000s, the SQL Slammer worm rampaged through networks like wildfire. Why? Because internal network segmentation was weak or absent. All it took was one infected server, and the whole infrastructure was compromised.

With microsegmentation, lateral movement is limited — so attackers or malware can’t jump from server to server. It protects servers by:

1. Restricting access: Communication is possible, but only to the extent necessary. No more open traffic to all servers.
2. Threat isolation: If an attacker makes it through, they only take down a small microsegment rather than an entire network.
3. Dynamic policy enforcement: Fortinet firewalls provide the ability to create policies that are dynamic — adjusting based on risk, user behavior, and traffic patterns.
4. Boosting compliance: If you work in banking, health care, or any regulated field, you must segment your environment, as required by frameworks such as PCI DSS, HIPAA, and ISO 27001.

Moreover, better segmentation greatly simplifies forensic investigations. In case anything does go wrong, you’re left with clear logs, isolated breach points, and a streamlined response process.

How to Implement Microsegmentation with Fortinet

Now here comes the big question — how do you do this with FortiGate firewalls?

Microsegmentation is not a plug-and-play solution. It requires strategically controlling the flow of traffic. Here’s how to do it:

Step 1: Define Secure Zones

First, identify your critical infrastructure and create logical groupings of servers based on:

• Web, Database, Internal Services (application type)
• User access requirements
• Compliance needs
• Risk level

Say goodbye to flat networks where everything can talk to everything. Every zone should have a very specific, well-documented purpose.

During this step, FortiGate firewalls can be deployed for segmentation. Fortinet’s FortiGate firewalls handle microsegmentation through:

• Policy-based segmentation: Control traffic flow using policies, beyond VLANs.
• IPS and Application Control: Scrutinize traffic at a profound level to prevent the spread of malicious activity.
• Zero Trust Network Access (ZTNA): Ensure authenticated users and devices have appropriate access to relevant segments.

Recently, I assisted three banks in deploying this setup, and the resulting network security improvement was significant. Before implementation, vulnerable user accounts could access multiple systems laterally. Afterward, attackers had to bypass multiple isolated defenses to reach another segment.

Step 2: Leverage Fortinet’s Security Fabric for Visibility

Fortinet excels in visibility, thanks to integration with tools like FortiAnalyzer and FortiManager. These tools offer:

• Fine-grained visibility about who’s accessing what (and when).
• Unified security policy control, allowing one to change a policy on a segmented environment easily.
• Automated threat response via FortiGate firewalls, effectively blocking suspicious activity in real-time.

Step 3: Regularly Test and Monitor

Too many companies configure microsegmentation once and then fail to monitor or test it. This is a mistake. Constant monitoring and routine assessments ensure that policies are still effective. Key steps include:

• Perform frequent penetration tests to check for vulnerabilities within microsegments.
• Check for policy drift, as over time rules might permit unintended traffic.
• Adjust configurations based on actual usage patterns, since networks evolve constantly.

Microsegmentation Solutions by PJ Networks

This is where you need expertise. At PJ Networks, we’ve spent the last several years securing critical infrastructure in financial institutions, enterprise networks, government entities, and more.

Unfortunately, many companies struggle with microsegmentation due to three primary challenges:

• Overcomplicating it with excessive rules that disrupt operations.
• Half-baked implementations designed only to pass audits but still leave admin networks exposed.
• Ignoring it completely, assuming firewalls alone are sufficient.

We specialize in practical approaches to microsegmentation that:

• Stop lateral movement in its tracks.
• Enforce intelligent security practices using Fortinet’s Full Security Stack.
• Deliver high performance without compromising security.
• Ensure compliance without disrupting operational effectiveness.

If you haven’t adopted microsegmentation, your attack surface is likely much larger than you realize.

Conclusion

Perimeter security is no longer enough. In today’s world, insider threats, advanced attackers, and zero-day vulnerabilities are constant risks.

Microsegmentation with Fortinet firewalls is not just a beneficial upgrade — it’s a necessity for securing servers and stopping threats before they spread.

Yes, implementing it can be challenging. But the alternative — leaving your critical systems open to unchecked lateral movement — is far worse.

A properly implemented microsegmentation plan can stop breaches in their tracks, and Fortinet’s technology ensures that you can achieve it effectively and efficiently.

It’s time to secure your segments before an attacker does it for you.