Get MAC address of a directly connected device Given a Linux server with an ethernet card, another device say an unconfigured router is connected with a patch lead (or an ethernet lead cabled in a different way if needed). They're both powered up. Is there a way on the linux box to get the MAC address of the other device? There's no IP network going on here just two connected ethernet interfaces. EDIT: The devices that this is concerning come with base config expecting to get an IP off a DHCP server which I can run on the linux host and work off that as soon as they get their temp IP.

If I'm not mistaken, ARP could be used to receive a MAC address of a machine. If you are connected at the data-link layer, I believe you can execute `arp -an` on a Linux machine to retrieve the MAC addresses of connected devices.

I've only used it to retrieve the MAC address associated with IP addresses, as that's what its usual function is - however due to the connectivity being over layer two, and that it uses the Ethernet broadcast address (FFFF.FFFF.FFFF), it should hopefully be able to retrieve the MAC address alone without an associated IP address.

I'm not actually able to test the above theory, but please let me know if you have any luck.