Hi Boštjan,
We are also experiencing strange behaviour of TMG 2010 on WinSrv2008R2 (a Hyper-V VM), namely, the TMG 2010 suddenly stops communicating via the internet-facing network interface, thus resulting in complete loss of internet connectivity for the company.
It's been driving us up the wall.
Reboot of the entire virtual machine running TMG helps.
Temporary fix:
Created a batch that runs every minute automatically rebooting the server in case it loses connectivity as this may happen during nighttime, which is especially problematic for us. The batch script is:
set ip="google.com"
ping -n 2 %ip% | find "TTL"
if errorlevel 1 shutdown -r -t 20
As for a more permanent try for a solution, I am reverting the VM to the backed-up state from June 30 this evening to try and determine definitively whether it was the July updates that broke it...
Main trouble is the logs don't say anything about why this might be happening, moreover there's no pattern to this, sometimes it's up for 12 hours, sometimes 36, ...
Did July 2018 updates screw TMG on 2008 r2?
