topic GlobalProtect - Slack split tunnel stopped working for some users in GlobalProtect Discussions

GlobalProtect - Slack split tunnel stopped working for some users

brianhill88 — Wed, 02 Feb 2022 02:34:52 GMT

Hello,

I have a case open but I thought I would post here in case someone had seen this. Most of our users use GP client 5.2.6. We are going to force an upgrade to 5.2.8 soon. In the mean time we have encouraged people to start upgrading when they have a chance so the whole company isn't force upgraded at once. Most people don't have any issues but incidents have started to trickle in with people losing access to Slack after the upgrade. We split tunnel all the slack URLs for all users.

Things we have tried:
* disable IPv6 on the NIC
* uninstall GP, reboot, reinstall. We did this with 3 different versions for one user who still has the issue. she is currently running 5.2.10.
* verified the firewall is not seeing Slack traffic (although we do see port 137 traffic which seems to be a common issue seen in the Live community but Slack doesn't use 137)
* had user use a wireless hotspot at home to rule out issues with their home network
* had same user use a different machine at home and on that one Slack works while on VPN.

* performed wireshark capture on non-working machine and it appears that DNS resolves Slack and then tries to connect but never receives a response.
* this makes us think there is some strange issue on the machines themselves

Haven't tried deleting the registry entry for Globalprotect yet on those machines.

Re: GlobalProtect - Slack split tunnel stopped working for some users

brianhill88 — Wed, 02 Feb 2022 21:35:15 GMT

Update: One of our techs tried removing the GP registry entry along with the uninstall and that did not fix the issue. This is only happening on Windows machines. We haven't seen it happen on Macs.

Re: GlobalProtect - Slack split tunnel stopped working for some users

brianhill88 — Mon, 14 Feb 2022 23:07:26 GMT

Finally figured it out. There must have been some windows update that pushed a driver update for the NIC. In this case it was Killer wireless NICs running a driver from 10/21. I was able to test a USB ethernet adapter on one of the affected laptops and it worked fine with that NIC. I then upgraded the Killer NIC driver to the driver from 1/22 and the problem went away. Not sure what the 10/21 version was doing but if you see a similar issue updating will probably solve it for you.