How does the /sys/class/net/ethx/carrier field get set?
I am trying to understand this field as it determines if a network cable is plugged in, but I am curious how it knows. This is specifically in regards to 10Gbase-KR and 1Gbase-KX.
I have a little knowledge in regards to CMSA/CD, but that is only for half duplex and NPL - pulses are for auto negotiation.
Is something going across the medium when no traffic is being sent?
I believe it may have to do with IDLE symbols, but I do not fully understand them.