[PLUG] ARP black magic question

[Galen Seitz]

Eric Harrison <eharrison at mail.mesd.k12.or.us> wrote:

> >> That is, when some random host sends out an arp query "who has serverb?",
> >> Server A needs to respond "serverb is at 01:02:03:04:05:06", where 
> >> "01:02:03:04:05:06" is the real MAC address for server B. 
> 
> >The question is, do you want to proxy an IP or a mac address?
> 
> I'm not trying to _proxy_ arp. The kernel doc's say that proxy_arp
> forwards arp packets between two devices attached to different media.
> 
> I'm trying to get one server to respond to arp requests for another
> server on the same physical network. Proxy arp doesn't work in this case,
> or at least I have not figured out how to bend proxy arp in that fashion...

Now I really am confused.  If serverB is on the same wire, why can't it
respond to the ARP request?  Is serverB slow to respond to ARP requests,
or does it not respond at all?  Is it correct to say that you want 
something like proxy arp, but for a single segment?  Perhaps you could
hack arpd to do what you want.

galen