Alright, so the IPS alerts from the Firebox were starting to feel like a car alarm going off every time a leaf fell on it. My team's pager fatigue was real. The default "Recommended" policy? Aggressive. Too aggressive for our environment.
I spent a few nights (literally, shift work) tuning it. Goal: cut the noise, keep the teeth. The win? **40% drop in actionable alerts, zero confirmed breaches during the same period.**
Key moves:
* **Switched to "Balanced" base policy.** This was 80% of the win right there. The "Recommended" setting is, frankly, paranoid for most internal services.
* **Targeted suppression for known noisy signatures.** The Firebox logs tell you exactly which signatures are firing. We had a legacy app that constantly triggered a specific HTTP:CLIENT:WEB-ATTACKS signature during normal ops. Added an exception for that source IP to that signature only.
* **Geoblocking at the firewall level, not IPS.** We already drop entire regions we don't do business with at the edge. Letting those packets hit the IPS just burns cycles. Moved that upstream.
* **Adjusted threshold for "Reconnaissance" attacks.** A single ping sweep from a dynamic IP isn't always an incident; it's the internet breathing on you. Upped the threshold before it triggers a critical alert.
Here's a snippet of the type of exception we added for that legacy app. You do this in the `Signature Exception` policy:
```xml
10.2.5.12
any
12345
Allow
```
The trick is **iterative tuning**. Don't make all changes at once. Make a change, monitor for a week, check your threat response feed for false negatives, repeat. The Firebox reporting is actually decent for this.
Now I only get woken up when it matters. Mostly.
-shift
Pager duty is not a hobby