How to find MAC addresses on network?

[Chris G]

On Fri, Jan 23, 2009 at 06:44:40PM +0100, Thomas Kaiser wrote:
> Chris G wrote:
> > On Thu, Jan 22, 2009 at 11:04:44PM +0100, Thomas Kaiser wrote:
> >> 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.
> >>
> > Thanks, works for just about everything except the HP printer, that
> > returns:- 
> > 
> >     hp7310                           (incomplete)                     eth0
> > 
> > 
> 
> So, that means there is now MAC address in the cache. And that means you 
> could not connect to the printer!
> 
> Can you print with this printer?
> 
Yes, when I connect it!  I found the plug had fallen out - oops!  :-)

However, even when it's working correctly, the printer doesn't give
its hostname when it gets its IP address via DHCP.  Everything else on
the network gives a name but this HP printer doesn't.

-- 
Chris Green