Path: utzoo!mnetor!uunet!munnari!kre
From: kre@munnari.oz (Robert Elz)
Newsgroups: comp.dcom.lans
Subject: Re: Latest news on our ether errors
Message-ID: <2011@munnari.oz>
Date: 27 Feb 88 21:20:01 GMT
References: <8403@g.ms.uky.edu> <4097@lll-winken.llnl.gov> <678@kaos.UUCP> <2356@umd5.umd.edu>
Organization: Comp Sci, Melbourne Uni, Australia
Lines: 20
Summary: A hack to avoid the ARP/ICMP dilemma

> >There's a variable in the kernel which controls IP forwarding
> 
> If you turn forwarding off, then you will get ICMP
> unreachable messages instead of the ARPs.

If you don't want to, or can't hack your IP code, then ..

There's one hack that you can do if you have a host that can publish
proxy ARP's .. arrange to have the "bad" IP address (the thing with the
trailing 255's) published by some ARP server, with a totally bogus
ethernet address for it (anything that doesn't exist on your cable).

Hosts that know 255 is broadcast will never arp for it, others will
learn the bogus address and forward future packets to that.

This doesn't save any ethernet traffic, but keeps it out of the way
of all the hosts that neither want to receive a hundred ARP requests
nor a hundred ICMP's when 100 old 4.2 hosts geceive a new broadcast.

kre