Introduction

I’ve been in this industry long enough to witness some really bad days — like the Slammer worm ripping through networks back in the early 2000s. In those days, intrusion prevention didn’t even exist. You just dealt with the aftermath and made sure that security would be tight going forward. But these days, we no longer have to wait for disaster to occur — we can interdict attacks in real time. That’s precisely why Fortinet’s Intrusion Prevention System (IPS) is vital for server security.

I have personally deployed Fortinet IPS to secure banks, enterprises, and data centers. It works. But only if you set it up correctly. Here’s a guide to using Fortinet IPS to protect your servers—your next cyberattack is already being planned, somewhere.

What is Intrusion Prevention?

Intrusion Prevention: When the firewall fights back. It’s not simply filtering packets—this is actively addressing malicious activity at Layer 7 of the OSI model in a way you can see, log, and block before it ever hits your network.

Unlike simple firewalls (that will just accept or deny traffic against a set of rules), IPS inspects traffic for nefarious intent, identifying patterns, matching against exploit attempts, and preventing them in real-time. It works on various layers:

• Signature-based detection. Identifies known attack patterns (e.g. SQL injections or buffer overflows).
• Anomaly-based detection. Flags abnormal behavior (like a server that suddenly starts blasting oodles of data).
• Heuristic-based detection. Stops new threats with behavioral analysis.
• Rate-based detection. Protects against distributed denial-of-service (DDoS) attacks.

The concept is exactly that: stop threats from hitting your servers. Because once malware gets in… clean up is a nightmare.

How Fortinet IPS Works

Fortinet IPS sits in the FortiGate firewalls I use and I trust it because it’s one of the few solutions that truly stop attacks in real-time without bringing performance to its knees. Here’s how it operates:

• DPI: Deep Packet Inspection scans the traffic in the application layer. Do attackers think they can hide inside encrypted traffic? Think again.
• Consolidated Threat Intelligence: Fortinet maintains a current database of known exploits, vulnerabilities, and attack techniques. IPS updates by itself without breaking a sweat.
• Preventive vs. Detection (Inline): Unlike standard IDS, which only logs the occurrence of evil doing, Fortinet IPS prevents threats while it happens.
• Custom Rules: You can define your IPS policy, securing your attack surface the way you want it to be (because who trusts default settings, right?).

One of the coolest features? IPS aligns nicely with Fortinet’s Zero Trust Architecture. This means that even if an attacker manages to penetrate your network, IPS will reduce lateral movement because it can prevent them from moving around between internal servers. That’s the distinction between a managed incident and a crippling breach.

IPS Best Practices for Servers

Now, here’s the thing. Fortinet IPS is not a guarantee that you are secure. I’ve walked into organizations that had IPS turned on—and they were still getting destroyed by attackers. Why? They didn’t set it up correctly.

If you really care about protecting your servers, here’s how:

1. IPS must be enabled on all critical segments.
   • Don’t merely apply it to your perimeter firewall. Internal traffic should be checked also.
   • Apply IPS on any VLANs that host databases, application servers, or cloud services.
2. Use the right IPS policy.
   • Adjust IPS profiles for your specific security needs (e.g., web-facing servers need aggressive web attack protection).
3. Keep IPS signatures updated.
   • New threats emerge daily. Outdated IPS rules, and they just walk right through.
   • Updating automatically – Fortinet’s threat intelligence feed is worth its weight in gold.
4. IPS rules can be reconfigured to prevent impact on performance.
   • One mistake I see? Admins enable ALL signatures. That’s a guaranteed way to choke bandwidth.
   • Instead, you should focus on high-risk signatures specific to your environment such as database exploits, web attacks, and known zero-day vulnerabilities.
5. Watch IPS alerts (not to the point of alert fatigue).
   • Learn what an attack was and whether there are additional threats probing your network if an attack gets blocked.
   • Filter out low-priority alerts so that the SOC team does not get inundated with noise.
6. Enable SSL Inspection.
   • The majority of attacks today hide inside encrypted traffic.
   • If IPS does not inspect SSL traffic, you are blind to 90% of threats.

A Quick Take: Avoid These Mistakes With IPS

In a rush? Here are the typical IPS blunders I observe — and what makes them perilous:

• Turning IPS detection only. That’s like putting in a burglar alarm while leaving your door unlocked.
• Ignoring internal traffic. Attackers enjoy hopping from one server to another.
• Not paying attention to performance. IPS is supposed to stop threats, not slow your network to a crawl.
• Not performing ANY SSL inspection. Because the attackers know you’re skipping it.

IPS is just set and forget, right? It’s not. Manage it actively, or it will not save you when it really counts.

IPS Deployment Services for PJ Networks

I’m not just discussing this—I’ve deployed Fortinet IPS for real-world issues.

PJ Networks specializes in:

• IPS rules tuning so only the threats that matter to you are blocked.
• Performance optimized deployments so that you get enterprise security without network slowdowns.
• Zero Trust IPS setups so attackers cannot move laterally within your network.
• Continuous monitoring and threat intelligence assimilation.

I’ve tightened the IPS of three banks this year alone (and learned a lot in the process). They each had their own blind spots—and so will your network. That’s where an expert eye has a big effect.

Have some servers that need to be protected? Let’s talk.

Conclusion

Security is continually evolving—and attacks are faster than ever. But you don’t need a disaster to force your hand.

With Fortinet, IPS prevents attacks before they become breaches. It inspects packet traffic, analyzes threats live and keeps the criminals out — if you set it up properly.

So take advantage of it. Deploy IPS all the way beyond your perimeter, tune the rules and enable SSL inspection. Now, before you become the next cautionary tale. Because trust me — I’ve cleaned up enough breaches to know this is one tool you do not want to skip.