RPi 3B+, InnoMaker amp hat, freshly written SD card - Setting static IP using the Volumio Network GUI results in a Pi that is NOT accessible from the network. This would NOT be such a problem normally, but this RPi is connected behind a network media bridge. I cannot rely on the correct MAC address reaching the DHCP server to assign a reserved IP address. 
Please advise best command-line Linux method to successfully configure eth0: as static IP. I cannot determine which particular variant/release of Linux is running. All I know is, it’s kernel version 4.x, which is great. Thank you in advance for any helpful advice you might be able to supply!!