get_mac works only for lan1 and lan2
eth0: link/ether 20:97:27:3d:02:69 brd ff:ff:ff:ff:ff:ff
lan1@eth0: link/ether 20:97:27:3d:02:69 brd ff:ff:ff:ff:ff:ff
lan2@eth0: link/ether 20:97:27:3d:02:69 brd ff:ff:ff:ff:ff:ff
lan3@eth0: link/ether 02:00:01:00:00:02 brd ff:ff:ff:ff:ff:ff permaddr 20:97:27:3d:02:69
lan4@eth0: link/ether 02:00:01:00:00:03 brd ff:ff:ff:ff:ff:ff permaddr 20:97:27:3d:02:69
lan5@eth0: link/ether 02:00:01:00:00:04 brd ff:ff:ff:ff:ff:ff permaddr 20:97:27:3d:02:69
lan6@eth0: link/ether 02:00:01:00:00:05 brd ff:ff:ff:ff:ff:ff permaddr 20:97:27:3d:02:69
lan7@eth0: link/ether 02:00:01:00:00:06 brd ff:ff:ff:ff:ff:ff permaddr 20:97:27:3d:02:69
lan8@eth0: link/ether 02:00:01:00:00:07 brd ff:ff:ff:ff:ff:ff permaddr 20:97:27:3d:02:69
lan9@eth0: link/ether 02:00:01:00:00:08 brd ff:ff:ff:ff:ff:ff permaddr 20:97:27:3d:02:69
lan10@eth0: link/ether 02:00:01:00:00:09 brd ff:ff:ff:ff:ff:ff permaddr 20:97:27:3d:02:69
switch: link/ether 20:97:27:3d:02:69 brd ff:ff:ff:ff:ff:ff
switch.1@switch: link/ether 20:97:27:3d:02:69 brd ff:ff:ff:ff:ff:ff
switch.23@switch: link/ether 20:97:27:3d:02:69 brd ff:ff:ff:ff:ff:ff
