Re: Proxy ARP

[Ryota Ozaki <ozaki-r%netbsd.org@localhost>]

On Fri, Feb 26, 2016 at 5:02 AM, Robert Swindells <rjs%fdy2.co.uk@localhost> wrote:
>
> Robert Elz <kre%munnari.OZ.AU@localhost> wrote:
>>When a host is answering ARP queries for an IP address that is not its
>>own, there are two ways (and reasons) for how it does that.
>>
>>It can send its own MAC address (kind of claiming ownership of the
>>IP address, though all it will usually do with the packet is relay it
>>elsewhere.)
>>
>>Or it can send someone else's MAC address - so that the host that sent
>>the query gets told the MAC address of the owner of the IP address (one
>>hopes.)  This was used in the ancient times Christos mentioned when some
>>hosts existed that did not understand ARP (IP over ethernet existed before
>>ARP was invented.)
>>
>>One of those was known as proxy ARP, the other wasn't - but I'm not sure
>>the nomenclature has remained consistent over time.  Any rational need for
>>the second form vasnished long long ago, I can't imagine any host still
>>running which understands both IP and ethernet, but not ARP.
>
> I have an emulated host that runs on NetBSD that doesn't understand
> ARP but will talk BOOTP and TFTP to a tap(4) interface.
>
> I'm fairly sure I only used the 'pub' keyword to arp(8) on the server
> to get things to work. Can check this.

Could you provide your setup and netstat -nr and arp -na outputs?
I try your setup and write some tests for it if possible.

Thanks,
  ozaki-r