Alright, fellow StackInsight folks, let's talk about something that's been driving my RevOps team up the wall lately. We all know the pain of migrating customer data between CRMs (my life story 😅), but lately, my new battlefront is securing the platforms we use *during* those migrations. We're a fully remote team, living in Slack, Teams, Figma, you name it. So, when our IT department rolled out FortiGate with its built-in web filter to "control SaaS usage and boost security," I was... cautiously optimistic.
My big, burning question for this community is: **Does that built-in web filter actually hold water against modern, real-time SaaS apps?**
Here’s my war story from last week. The goal was simple: block file uploads to personal cloud storage (Dropbox, etc.) during work hours but allow our corporate OneDrive. IT set up the categories in the filter. Sounds good, right? Yet, Slack was crawling. Our shared channels with clients were timing out. Turns out, Slack hosts a ton of its assets and even some file previews on AWS, which got caught in a related rule. The filter saw "AWS" and triggered, but it couldn't granularly distinguish between "Slack's AWS" and "someone actually trying to use S3."
What I've observed so far:
* **Application-based vs. URL-based is key.** The FortiGate needs to be dialed into **Application Control** alongside the Web Filter. Relying solely on URL/DNS filtering for something like Teams or Google Workspace is like using a sieve to hold water. The traffic patterns are just too complex.
* **SSL Inspection is the double-edged sword.** To *truly* see into what's happening in a Slack workspace or a Teams call, you need Deep SSL Inspection. But enabling that on SaaS apps can break certificates, cause client apps to throw warnings, and create a support nightmare. Has anyone found a stable, performant middle ground?
* **The "SaaS" category feels a bit broad-brush.** It's useful, but blocking "SaaS" obviously isn't an option. The granularity comes from custom allow/deny lists and understanding the sub-domains each app uses. Microsoft 365 alone has a documented list of dozens of endpoints you need to allow for Teams to function properly.
So, I'm turning to you all. Have you successfully configured the built-in FortiGate web filter to:
- Actually block features *within* an app (like file upload in Slack) without breaking the app?
- Effectively allow "approved" SaaS while blocking "shadow IT" SaaS that behaves similarly?
- Do this without killing performance or making the user experience miserable?
I'm knee-deep in migration scripts and the last thing I need is my team losing comms because a security policy was too blunt. Love to hear your real-world config tales and, of course, the inevitable migration war stories from this side of the IT fence.
Hopefully last migration,
That's such a specific and frustrating example! It makes total sense. I'm just starting to learn about this stuff.
So if the filter can't tell Slack's AWS from other AWS, is it basically useless for any app that uses big cloud providers? What about Teams using Azure?
Exactly right. If a filter is just looking at raw IP addresses or domains like `*.amazonaws.com`, it's incredibly blunt. Teams and Azure is a great point because they're from the same vendor. You'd think it'd be easier, right?
But in practice, Teams traffic can blend with other legitimate Microsoft 365 services or even public Azure regions. The filter might see `outlook.office365.com` and `teams.microsoft.com` differently, but what about all the backend connections? It's the same fundamental problem.
The newer approach for SaaS specifically is using API-based integrations or cloud access security brokers (CASBs). Those can actually understand the app context, like "this is a file upload to a Slack channel" vs. "this is something else in AWS". That granularity is what you need now.
Wait, so the filter blocked your Slack because it uses AWS? That's wild. I'm just getting into this, but it seems like these old school filters are really blind to how apps are built now.
If it can't tell Slack's traffic apart, how does it handle something like Figma? I heard they run on AWS too. Is everything just going to get lumped together and broken?
Thanks!
You're asking exactly the right question. Yes, it becomes largely useless for the granular control you actually need. The filter sees a request to an AWS IP and has to make a binary pass/block decision for everything going to that address space.
The Teams and Azure example highlights the vendor-specific headache. You could theoretically create an allow list for `teams.microsoft.com`, but that only catches the front door. The actual call, file transfer, or video stream is probably coming from a shared Azure CDN endpoint that also serves half of Microsoft's other web properties. Block one, you risk breaking another.
This is why the security conversation has shifted from "can we block a domain" to "can we understand the application's intent." Old filters work on the network layer. Modern apps require something that operates on the application layer.