I have a systemd host with 4 ethernet ports.
one port is reserved for isolated containers. It is set as:
# /etc/systemd/network/20-eth3-reserved.network [Match] Name=eth3 [Link] Unmanaged=yes I also set aliases for the ports, each on its link file, e.g.
# /etc/systemd/network/12-alias-eth3.link [Match] MACAddress=42:42:42:42:42:03 [Link] Name=eth3 I would later use the unmanaged interface in a systemd-nspawn container with
# /etc/systemd/nspawn/container1.nspawn ... [Network] Private=yes VirtualEthernet=no Interface=eth3 At some point (Sept) it was working fine. But a few months ago, the interface with unmanaged setting just vanishes from the system.
nspawn fails to bring up the container saying the interface was not found.
ip link shows no eth3, nor the mac address.
lshw weirdly shows all managed ports, but DO NOT list the macaddress (serial field) for the disabled one.
dmesg shows all ports just fine, and list the correct mac address of them all, including disabled one. Later on, it also show the alias being applied!
[Wed Nov 10 11:44:31 2021] igb 0000:03:00.3 eth3: renamed from enps0f4 So systemd does see the device just fine even after the problem started.
networkclt shows all managed ports plus lo as unmanaged. But no sign of eth3.
I don't mind finding the solution to this if there's a better way to 'reserve' a physical interface to be used with nspawn instead of Unmanaged=yes
