Interface settings mystery

[dwasifar]

Recently I switched to an Awow AZ51 micro PC for OPNSense.  This device has two 2.5Gb ports, and most users report having to change settings to get full throughput.  When I set it up initially, I got limited throughput, and found I needed to set the Speed and Duplex setting for each interface to 1000BaseT, and got full speed.

Today, to troubleshoot a different issue, I had to revert to an older saved configuration, which did not have the Speed and Duplex setting.  After a reboot, imagine my surprise when I got full speed without changing the Speed and Duplex setting from "Default."

I'm happy about it, but I don't understand it.  Could the hardware interface have remembered the setting?

[bartjsmit]

I suspect layer 0 gremlins. Did you buy a decent CAT6A cable?

[newsense]

Depending on what's on the other side of the cable autonegotiation may fail or be hit and miss.

It's best to control it on the FW side in this case.