How to find MAC addresses on network?

[Thomas Kaiser]

Chris G wrote:
> Is there a (reasonably) straightforward way of finding the MAC
> addresses of systems (well, strictly, interfaces) on a network?
> 
> arping works for some but not all of my hardware, presumably some
> things (like my HP printer) don't respond to arping.  What can I use
> to find the MAC address of the printer?
> 

Connect to your device somehow (http, print a document) and after run 
"arp" in a terminal. The MAC addresses of the devices you connected 
stays in the ARP cache of your computer for some time. "arp" just shows 
the cache.

Thomas