CC BY-SA 4.0 - Dmitry Nosachev Ethernet is everywhere, tens of thousands of hardware vendors speak and implement it. However almost every ethernet link has one number in common, the MTU: $ ip l 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: enp5s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP link/ether xx:xx:xx:xx:xx:xx brd ff