ARP learning

[cyberzeus]

I know the ARP table can be populated due to receiving an answer to an ARP request or via static entries however, I'm seeing intermittent instances of a given MAC showing up without receiving any ARP response.  With this in mind, can the ARP table be populated by merely receiving packets on a given interface?

If so, can this behavior be disabled or tuned at all?

[pfry]

I don't see documentation to that effect, but it would seem to save a bit of time and bandwidth. It may learn from ARP requests as well, but testing this might be inconvenient.

I don't see much in the way of ARP controls.