Understanding Dynamic Groups, LDAP Sync, and Policy Automation in FortiAuthenticator

It’s 3rd coffee o’clock here at my very cluttered desk — papers, half-empty mugs and a whiteboard filled with notes on zero-trust architectures and sync strategies. I cut my teeth as a network admin in ’93 (yeah, before most of you were deciding which IT career to pursue) and have seen technologies come and go—some gracefully, others like a car losing gears. Let me tell you — when the Slammer worm struck, it was like driving that car with a blind fold on and in a thick fog. Fast forward, now I run P J Networks Pvt Ltd and have just delivered projects to upgrade three banks’ zero trust architecture. One of many lessons learned? The human factors and business logic drama around dynamic user group listing synchronization between AD/LDAP and FortiAuthenticator.

The never-ending struggle with user groups in security

(JKT) Data security 101, lesson learned Good rule of thumb when deleting users, moving CSVs to staging, and lead form providers Pivoting for huge accounts, writing bad Python, user groups in security (TUT) This is what you’re building when you start from $20+ million ARR(pages and features), feeling paranoid and what accounts are you in control of OPIDoodles for revenue and customer acquisition in the year of the capitalist* In August 2019, we posted summarized learnings from our product development. Static groups are just like turning on your cruise control on an empty highway. Convenient, sure. But what if the road moves? When a user is added, or role is updated? Manual syncing? Oops — you’re trailing so far behind you’re missing out faster than your firewall’s capacity to inspect during a massive DDoS.

1. Group Mapping: The Power Behind Syncing

When I first began trying to get my head around group sync, all the way back to the fintech reboot, mapping AD groups to FortiAuthenticator user groups felt very much like trying to fit the pieces of one jigsaw puzzle with pieces of another.

• The secret: Get to know your current directory structure well.
• Write down what user fields contribute to your FortiAuthenticator policies.

We categorize groups at PJ Networks into dynamic sets by role, or by department—it is an automated recipe sorting your ingredients for the cooking action. The LDAP groups (or AD security groups) end up being the pantry, and FortiAuthenticator wants explicit directions on what ingredients (users) to select and at what intervals.

But the funky nested groups and legacy LDAP schemas don’t even get me started—it’s the floppy hair of your group mapping, and serves no purpose but to look like a bowl of mixed salad with no dressing. The trick?

• Use the LDAP query filters.
• Give your AD clear names.

This prevents the mistakes then the FortiAuthenticator only takes the necessary users, no more, no less.

2. Sync Rules: The Automator’s Friend Forever

This is where FortiAuthenticator pulls its weight – it’s not just turning on 2FA. With no firm sync rules, you’re babysitting an old petrol engine rather than running the system smoothly on autopilot. Our method at PJ Networks is as follows:

• Carefully defining sync intervals. Too frequent? Network hog. Too sparse? Stale data.
• Partitioning which groups sync by their activity or importance.
• Mapping characteristics such as email, department, job title etc from the identity to Forti and make them profile fields - It shouldn’t only be cosmetic but needed for the OR policies themselves.

Here’s what I do — always test these rules in a staging environment first. There’s nothing like the fear of pushing sync rules live and losing half your user groups to a typo or badly worded query. Yes, that happened once. Facepalm.

And honestly, Forti’s GUI could use some more spice here. Their LDAP sync isn’t drag-and-drop intuitive complete with a billion leverage points and a braided wiring harness that keeps getting tangled.

3. Applying Policy: From Interest Groups to Action

Great, so now you have your groups mapped, have massaged the sync rules just right, the users flow freely into FortiAuthenticator. Now what? Policy automation.

Here’s an analogy I like: imagine policy application as if you could set your car traction control to automatically adjust to road condition. Same groups, but different policies for level of risk, time of access, or form of device.

Dynamic groups empower:

• Fine grained access control without human interface.
• Automated enforcement of MFA policies, a necessity in modern zero-trust frameworks.
• Easier compliance reporting as policies are based directly on the memberships of the groups.

Helping some of those banks transition to a world where they could develop a zero trust model, I myself saw how syncing user groups dynamically could empower them to layer on conditional access policies on the fly—without needing to request IT for weekly “permission slips.”‍

One caveat: I’m still a bit confused about why some push complex AI-powered policy engines when simple group sync automated works just fine. A little skepticism by the community is good.

4. Sync Watch: Watching the Conveyorriage

Automation is not walkaway perfect. If sync is the conveyor belt, monitoring is the person waving his arms when something jams.

At PJ Networks, we are additionally extremely proactive when it comes to sync monitoring, treating it as our second line of defense to spam rejections:

• Turn on detailed FortiAuthenticator logs for LDAP activities.
• Configure notifications for failed syncs.
• Regularly compare synced groups vs source AD and have a process – review audit of this isn’t optional.

Pro-tip: surface a dashboard view for sync health. There is nothing like a dash of cursory scrutiny to spot a misapprehension before it leads to user lockouts or, worse still, vulnerabilities.

Remember the Slammer worm? You wouldn’t have to do that if you’d started watching your infected packets earlier and could isolate and contain so much faster. Same applies here – catching sync failures early can prevent us from misapplying policies and causing a breach.

Quick Take: What You Need to Know Right Now

• Dynamic groups keep your FortiAuthenticator user and group info up to date without any manual headache.
• It’s very important to get your group mapping right, treat it as you would careful prep of ingredients.
• Sync rules automate the flow and test everything twice — once isn’t enough.
• Dynamic group wired policies enable automated adaptive access — so long, manual updates.
• Automate but never forget you monitor—automatic sync needs a human.

Far too much credit and criticism has been laid at the feet of dynamic group sync; is is not, in fact, a silver bullet but an important component in a defense-in-depth approach.

Final thoughts

After nearly two decades in networking and cybersecurity, here’s what has become increasingly clear to me: Security is a lot like making a classic dish — you need the right ingredients (or user data), the right amount of processing (or sync rules), the right amount of heat applied at the right time (or policy enforcement), and you need to constantly taste and adjust the mixture accordingly (or monitoring). Leave something out, and the dish is weird-tasting — or worse, dangerous to eat.

And we have the leverage of FortiAuthenticator’s dynamic group sync, a powerful weapon for getting manual user management grunt work off our plates and reducing human error in the process.

That’s not to say the Forti GUI doesn’t have some kinks, or that we could do with more AI (the kind that helps you do the right thing instead of lying and eventually disappointing). But if you’re operating any serious environment — banks, enterprises, hell, even up-and-coming SMBs — you owe it to your security posture to nail dynamic user groups.

Oh, and one more rant—password policies. People, the strong policy to lock users down is nice, but if your sync barfs and users can’t auth, that castle might as well be a colander. Automation is not just a matter of convenience — it’s a matter of life and death.

So go pour yourself another cup of coffee (it’s 8 a.m. somewhere) and try to conceptualize group sync as the heartbeat of your FortiAuthenticator deployment. The engine idles — time to shift into gear.