If you are using the 8125/8125B NIC in unraid 6.9.2. Please manually block the r8169 driver, otherwise it will not use the r8125 9.005.01 driver.
WARNING: I don't know if this is the correct way to block the r8169 driver
Slackware seems to block drivers via a file created in:
/boot/config/modprobe.d
Depending on what you read, the file should be called either "blacklist" or "blacklist.conf" - I created both just to be sure.
The file contains a single line:
blacklist r8169
It seems to have works and I now see this line in the log:
Oct 27 18:45:03 kernel: r8125 2.