Subject: Re: arp table funzies
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: Perry E. Metzger <perry@wasabisystems.com>
List: tech-net
Date: 05/15/2002 13:37:36
der Mouse <mouse@Rodents.Montreal.QC.CA> writes:
> The major problem I see with arp(8) is that there is no way to specify
> what interface an arp entry is to be created on.  For "normal" arp
> entries, there is usually only one interface that makes sense, but for
> published (proxy) entries, this is not the case - and even for "normal"
> arp entries, I've found uses for arp entries pointing out a "wrong"
> interface.
> 
> Thus, I added a keyword "if" for use with -s, so that you can do stuff
> like
> 
> arp -s 10.1.2.3 0:1:2:3:4:5 if de2
> 
> to install an arp entry for that IP and MAC address, pointing out de2.

I like the idea, but I don't like the syntax. A -i flag or some such
is probably more in the spirit of things. (It might, in fact, be most
reasonable to *always* require the interface be specified in which
case a keyword or flag are both unneeded.)

> When using this to create proxy entries, you also have to be able to
> tell arp that it's supposed to be a proxy entry, because specifying an
> interface bypasses the normal logic for determining whether the entry
> is to be a proxy entry.

Maybe the logic should be fixed instead of the program?

--
Perry E. Metzger		perry@wasabisystems.com
--
NetBSD: The right OS for your embedded design. http://www.wasabisystems.com/