I am running Arch Linux under LXC. I have a systemd unit file for
dhcpcd (a DHCP client) that includes:
eth0 exists and is functioning:
# ip link show eth0 35: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000 link/ether 00:16:3e:05:24:4e brd ff:ff:ff:ff:ff:ff
Systemd does not appear to be aware of this interface, and ultimately gives up with the following error:
Timed out waiting for device sys-subsystem-net-devices-eth0.device.
This is what
udevadm says about the interface:
# udevadm info /sys/class/net/eth0 P: /devices/virtual/net/eth0 E: DEVPATH=/devices/virtual/net/eth0 E: IFINDEX=35 E: INTERFACE=eth0 E: SUBSYSTEM=net
Why doesn't systemd know about this interface? I would like to avoid modifying the existing service file (because it will probably get tromped on by a package upgrade, and because having the service depdend on the network interface makes an awful lot of sense).