enhanced config to select network interface by name.

[THKDev]

Need to advertise the right IP address over mDNS in case you have multiple interfaces or vlans.

Name of the interface (eg. eth0 or lo) or all or loopback
interface = vlan.1 # all | loopback | eth0 | vlan.1

[alexpevzner]

Hi,

It will not work, if interface can change its address dynamically.

To implement it, you will have monitor as interface addresses are changed over time and update your configuration on a fly.

Also, I dont't like the systemd service dependency on the network-online.target - looks like it will prevent service from running if network is disabled, while ipp-usb actually don't need the network for its functionality and usable without network connection to drive the locally connected printers.