Hey everyone, hoping to tap into the collective wisdom here. We've been rolling out Zscaler Private Access (ZPA) for our internal teams and external contractors, and overall it's been solid for the core workforce.
But we keep hitting a snag with our contractor group. Their access policies—specifically for a few key marketing cloud and analytics platforms—seem to randomly break. One day they can reach the BI tool, the next they're blocked. Our IT team points to clean logs on their end, and the contractors swear they haven't changed anything on their devices.
I'm wondering if anyone else has navigated similar issues, especially with non-employee users. A few specifics from our side:
* Contractors are in their own ZPA segment, with distinct access policies.
* The breaking apps are SaaS, using unique domain-based app segments.
* We use IdP groups for authentication, and the contractors are in the correct groups.
Potential leads we're chasing:
* Could it be an IdP group sync latency issue with Zscaler?
* Are there known quirks with contractor devices (like stricter local firewalls) interacting with the ZAPP?
* Is there a particular order-of-operations pitfall in policy creation we might have missed?
Really just looking for any real-world fixes or diagnostic steps beyond the obvious. It's creating friction with our external teams and slowing down campaign analytics. Any shared experiences or benchmarks would be hugely appreciated!
Cheers,
Henry
Cheers, Henry
Your hunch about IdP group sync latency is a solid place to look. We ran into something similar, and it turned out the contractor IdP group memberships were being updated outside of our normal sync schedule, causing ZPA's policy evaluation to temporarily mismatch. The logs can look clean because the policy *was* correct at the moment of logging, but the user's group context had shifted an hour earlier.
Have you checked the policy precedence order for that contractor segment? If there are multiple policies applying to the same apps, even a slight misordering can cause what looks like random behavior, especially if a broader "Deny" rule sits above a more specific "Allow" for contractors. The intermittent nature makes me think it's either a timing issue or a conflict, not a static misconfiguration.
Stricter local firewalls on contractor machines are also a common culprit, particularly if the Zscaler Client Connector service gets blocked from updating its configurations. That can lead to inconsistent tunnel health.
Support is a product, not a department.
You're absolutely right about the IdP sync being a likely root cause, and your point about the logs showing a technically correct evaluation is critical. That mismatch window can be surprisingly wide depending on your IdP's propagation speed and ZPA's session re-validation interval. We mitigated something similar by implementing a secondary, application-specific group in the IdP solely for ZPA access. That group's membership changes far less frequently than the broader contractor classification, which stabilized the policy context.
On the policy precedence note, I'd add that ZPA's evaluation logic for segments with multiple active policies can produce non-intuitive results, especially when combining user-based rules with device posture or location conditions. A contractor on a personal device might hit a different rule chain than on a managed asset, making the failure appear random. It's worth auditing not just the rule order, but the condition types in each policy that could apply to the contractor segment.
The local firewall angle is also valid, though in our case it manifested as the Client Connector failing to fetch updated App Connector IP lists, causing some sessions to route to a stale endpoint. A script to verify tunnel configuration state on the contractor machines helped isolate those incidents.
—BJ
Great point about the policy precedence order. It's easy to overlook, especially when you're managing multiple segments. One thing I've done is add a prefix to the policy name to force the ordering I want in the admin UI list, like `01-Allow-Contractors-BI` and `99-Deny-All-Else`. It's a simple visual trick that prevents accidental drag-and-drop mistakes later.
The contractor machine firewall angle is huge. We once spent days chasing "random" drops that traced back to a third-party endpoint security update on their devices, silently blocking the ZCC service. A quick script for them to run that verified the ZCC processes and required outbound ports saved us a ton of headache.
The prefix trick is smart for visual sorting. I'd also add a monthly audit step to that process. Policy precedence can drift after minor app updates or segment changes.
What's the actual ROI on that firewall check script vs. just enforcing a minimum ZCC version? For contractors, we found version enforcement more reliable than asking them to run diagnostics.
Ask me about hidden egress costs.