06-20-2019 06:13 AM - edited 06-20-2019 06:15 AM
So this is a weird one. I have several T480 laptops and the users use a program that requires a constant connection. The laptop is usually connected via USB C cable to the Lenovo USB-C Dock with Ethernet cable.
Once or twice a day the users report losing connection. This occurs if the user is on wired from the dock or wired from the laptop. Looking at the logs, it clearly states that the network port was "unplugged" but then plugged back in less than 1 second later. This breaks the connection for the program being used.
On a few, I've updated the bios and that fixed it. But the rest have no explination.
I've changed cables and docks but to no avail. I've looked at the switch logs and there's no issue there. And it very clearly says disconnected, not just disabled. The logs are exactly as though the cable was pulled out.
LAN and Wifi Drivers are up to date.
Windows version is 1709.
Dock firmware is up to date.
Bios is 1.24
06-20-2019 08:32 AM - edited 06-20-2019 08:34 AM
This is going to sound weird, but go into the BIOS and change the Thunderbolt 3 security setting (under Config) to No Security and give that a try.
Also, I'd recommend updating the machine(s) to at least 1803- 1709 is considered EOL unless you are running Enterprise/Education.
06-21-2019 12:46 AM
I'll do that. We have to do it on all our P52s but haven't had to on the USB-C docks yet.
Also, can't swap away from 1709. We're enterprise and the company isn't ready to update yet.