

It may also inadvertently expose it, for example by using it as the host part of its IPv6 address or otherwise including it in its layer 3 traffic, but you cannot rely on that, either.ī) The router forwarding packets from that network segment to you. You could simply ask it, but of course it may lie, so that's hardly useful if your goal is to unmask an impostor.

Possibilities:Ī) The remote host itself whose MAC address you want to retrieve. In order to get a MAC address from a network segment you are not directly connected to, you need the cooperation of a node which is directly connected to it. This is the underlying reason why ARP does not work across routers. It is stripped when a packet is passed to layer 3 (network layer).

The MAC address is a purely layer 2 (link layer) property.
