Subject: Adding [published] ARP entries for a subnet?
To: None <tech-kern@NetBSD.ORG, tech-net@NetBSD.ORG>
From: Jonathan Stone <>
List: tech-kern
Date: 03/24/1996 20:07:52

I'm wondering about adding the ability to do proxy-arp for an entire
subnet. The reasons I'd find it useful is for things like installing
an IP-level filtering router as a firaewll between some set of
machines and their link to the Internet, without _either_ the local
machines _or_ the ISP [sic] having to change anything.  Explicitly
listing 512 machines for proxy arp is, well, gross...

I'm assuming NetBSD doesn't do this already, as the source for arp.c
doesn't seem to support it. 

However, the PATRICA tree code _seems_ to have all the requisite
functionality: routes have subnet masks, and  "arp cache" and
route table are the same thing. So...

	a) has anyone tried this?  How about FreeBSD?
	b) What, if anything, is likely to break in the existing arp-lookup
	   code if I start adding "arp" entries with a subnet mask?

	c) is Core likely to buy it back if I make this work?

If anyone has any ideas on this, pro or con, or a better way to
achieve what  I'm trying, I'd appreciate hearing about them.

NB: Linux supports this already.

--Jonathan Stone