How do I set up granular app rules in Cato? The UI is confusing.

The UI's confusing because they overcomplicate simple concepts. Forget the "Application Rules" tab at first.

Go to Policies > Security. Create a new rule.
* Source: your user group
* Destination: Application > pick Salesforce
* Action: Allow

Then duplicate it for Slack. That's it.

If you try to use their "Application Control" wizard, you'll end up with 50 overlapping rules and a headache.

This works for trivial cases, but you'll hit a wall when you need exceptions. What if your "Salesforce" rule needs to block a subset of its risky sub-applications? Their grouping is monolithic.

You're better off in the Application Catalog under Monitor. Find the actual app signatures, then build rules using those. The pre-packaged "Salesforce" object is a blunt instrument.

That's a good point I hadn't considered. So you're saying the pre-made app objects can include unwanted traffic, like maybe file uploads within Salesforce. Using the Application Catalog to find specific signatures sounds more precise.

But how do you find the right signatures in the catalog for a big app like that? Is it just a lot of manual searching for patterns, or is there a trick to it?

Forget the beginner workflow, that's how you get a $300k cloud bill. They're trying to abstract things that shouldn't be abstracted.

The real problem is their application signatures are wrong half the time. I've seen "Salesforce" include random CDN traffic that should be blocked. You need to build your own allow list from scratch using actual traffic logs, not their wizards.

Go to Monitor, filter for your user group, and see what hits are actually tagged. Then copy those exact app signatures into a new policy. Anything else is guesswork.

Oh good, a simple walkthrough is exactly what I needed too. The other methods mentioned seem powerful but a bit intense to start with.

So following user400's first steps, I just tried making two separate allow rules under Policies > Security. It was straightforward to pick the user group and select the Salesforce application object. But I'm already wondering, when you duplicate the rule for Slack, should you keep them as separate rules or combine them into one? Does combining sources or destinations in a single rule cause any issues later on?

That's super helpful for getting started, thanks! Quick question on duplicating - if I have a whole list of allowed apps later, is there a risk of hitting a rule limit in the policy table? Or does Cato handle a bunch of simple allow rules okay?

A simple workflow won't save you when their classification is wrong. Start in Monitor, find the exact traffic patterns for your users, and build rules from there. Their pre-packaged 'Salesforce' object is a liability.

You'll end up allowing things you didn't intend and blocking things you need. Then you're back in the logs anyway.

Exactly. I've seen their "Slack" object allow half of AWS because they bundle every cloud service Slack might touch. You're better off writing a rule for slack.com and maybe one for files.slack.com, but only after checking what your users actually hit.

Their pre-canned objects are for people who want to click buttons without understanding what's happening underneath. If that's the case, maybe you don't need granular rules in the first place.

Good point about the Slack object pulling in AWS. I ran into that with their "Microsoft 365" object - it was letting through unrelated Azure management traffic because they grouped too broadly.

The tricky part is that `slack.com` alone often isn't enough. You'll usually need to also allow `*.slack-msgs.com` and `*.slack-files.com` for full functionality, but you have to confirm those are the only patterns in your own traffic logs first. It's a few more rules, but they're precise.

You're right, it can be a manual search, but the catalog's search is pretty decent. Try the "Contains" filter with the main domain or brand name. For Salesforce, you'd search for that and then carefully review the resulting signatures - they're often broken out by function like "Salesforce-Chatter" or "Salesforce-Platform".

My caveat is that even these granular signatures can be bundles. The "trick" is to pair that catalog search with the method user400 mentioned: check what's actually hitting your own sockets in Monitor first. That tells you which of the catalog signatures are relevant for your environment.

That's correct for Slack's current CDN structure, but be aware it changes. I've seen `*.slack-files.com` deprecated in favor of `*.files.slack.com` over a few months.

The principle stands: verify against your own live traffic before committing any signature to policy. Their published catalog can lag behind actual service updates.

That's such a key point about the catalog lagging. I've burned a weekend before because the published "Zoom" signature was two major versions behind and broke our video calls after an update.

It makes the verification step user400 keeps mentioning non-negotiable. I treat the app catalog more like a hint or a starting point for my own investigation in Monitor now, never as the final source of truth. Has anyone found a reliable way to get alerts when a major app you depend on changes its backend infrastructure? I just set calendar reminders to re-check my core app traffic every quarter.

That request for a simple walkthrough is understandable given the complexity of the initial UI. However, providing a step-by-step guide based on the pre-packaged application objects would likely set you up for the problems others have outlined. A truly beginner-friendly approach needs to include the verification step from the start.

I'd suggest a modified workflow: first, create a temporary "allow any" policy for your test user group and use the Monitor section to capture a baseline of their actual application traffic for a defined period. Then, search the application catalog not for "Salesforce," but for the specific domains and IP ranges you observed. This builds your rule from real data, not from a potentially misleading label.

Treating the catalog as a validation tool for your own findings, rather than as a menu to pick from, is the only way to achieve the granular control you're after without inadvertently creating security gaps or breaking functionality later.

This workflow is correct, but that temporary "allow any" policy is dangerous. Don't attach it to a user group, it's too broad. Use a dedicated test machine with a unique IP range or hostname and scope the allow-any rule to that source only. Even in a test, you don't want to expose all your users.

"Treating the catalog as a validation tool" is the key line. It means your rule logic is inverted. You start with data from Monitor, build a list of required domains/IPs, then use the catalog to see if Cato already has a clean signature for that exact pattern. If not, you build a custom app object. The catalog isn't your source of truth, your logs are.