Z-App stops forwarding traffic

(dgr) #1


I do have a support case open for this but wanted to see if anyone else has experienced this issue.

We find that Z-App intermittently stops forwarding traffic to ZIA. We are running Z-App in Tunnel mode with Windows Filter Drive (Packet Filter Based). The cause is unknown right now but when it happens the bytes sent and received in Z-App stop incrementing. The user has to log out of Z-App and then log back in to resolve the issue.

We were only made aware of the issue because we still have our old proxy servers in place with WCCP configured whilst we continue to fully migrate our estate to ZIA. On the old proxy servers we added a rule that displays a notification to the user if they hit the old proxies but they’re a member of the new Zscaler Users AD group.

Is it just us? I did ask the person working the support ticket to check for similar cases but apparently there are none.

Z-App version

(David Creedy) #2


This doesn’t sound normal no. If you can provide the ticket # I can have a look on the back-end.



(dgr) #3

Hi @dcreedy. Ticket #581627.

(dgr) #4

OK, so I wanted to provide an update to the community on this because I’m sure others may run in to this too. The issue is still on going but it appears we’ve had a bit of a breakthrough today.

The issue is related to the type of laptop docking stations we’re using. We have docking stations that connect via USB-C (moving away from traditional “port replicators”). With these types of docking stations, when the USB-C cable is connected to the machine a new Ethernet adapter appears.

Z-App does not re-evaluate the list of network adapters. It appears it only does this when the user logs in to Z-App.

So the scenario is: User has a laptop with Wifi. User is docked. Their connection is through Ethernet (Wifi gets disabled when Ethernet is connected in Windows). They undock and their connection switches to Wifi. The Ethernet adapter disappears from Windows (because the docking station is disconnected). They connect their laptop to the docking station again. The Ethernet adapter re-appears and after a period of time reconnects (Wifi gets disabled). But Z-App is not re-evaluating the list of network adapters and therefore is not detecting the network change and I assume it still tries to forward traffic out of the Wifi adapter which is now disconnected.

This is why we found that logging out and back in of Z-App fixes the problem because it forces Z-App to re-evaluate all of the network adapters.

I hope engineering are able to solve this problem soon.

(David Creedy) #5

I’m still following up with engineering on this.

It’s interesting because we subscribe to the OS notifications for network changes. If Windows detects a network change (e.g. plugging in LAN cable), we get the notification and re-evaluate automatically.

It’s not really clear to me why Windows isn’t notifying of the change in this event, but we will keep looking.

(Nik R) #6

Hello @dcreedy ,
We are having the same issue using Tunnel with Local Proxy.
Zapp never crashes, it stops filtering and sending/receiving bytes.
Ticket open is 659974
Can you please look into it?
We have users unprotected and no way of catching it because portal does not have a report to run and see users without web activity for certain period of time.

(David Creedy) #7


It looks like the ticket is progressing. Feel free to reach out if you feel it’s not getting the attention needed.