Haven't run into this in the past, or in testing with proxmox on a 1GbE network. But in my production network each node has 2x 1GbE interfaces, and 2x 10GbE interfaces. This generates eth0, eth1, eth2, and eth3.
Most of the time, eth0&1 are 1GbE, and eth2&3 are 10GbE. Thus in my...