Path: utzoo!mnetor!uunet!husc6!bloom-beacon!mit-eddie!ll-xn!ames!pasteur!ucbvax!VENERA.ISI.EDU!braden
From: braden@VENERA.ISI.EDU
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Subnetting
Message-ID: <8805100150.AA07641@braden.isi.edu>
Date: 10 May 88 01:50:38 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 29


	
	It'll still seem useful, though, OK, maybe not essential for hosts to
	be able to find the subnet structure of a net.  For sending directed
	broadcasts, suppose you want to say "broadcast on the net where host X lives"
	where X is known by name.  It might be desirable to use the normal mechanism
	for finding X's address rather than hard-wiring an IP address into an
	application.  In that case, since the domain name system doesn't (and shouldn't)
	record network structure, how could you find the right broadcast address?
	Admittedly this may stretch the point a bit but not too far, I think.

Stuart,
	
Directed broadcast is generally a poor idea (the right solution is the IP
multicasting).  No architectural decision should be taken on the grounds
that it makes makes directed broadcasting easier.
	
	Likewise, if a host and several gateways are on some (sub)net, the host might
	want to set up its routing tables for a "good" choice of gateway to other
	subnets.  Granting that routing should work if the host picks -some- gateway
	and depends on that to forward and/or redirect traffic as needed, it could
	still make good use of the information if it could get it.

I disagree.  The Internet standard approach for a host: pick any
gateway and let it redirect you... is simple and effective. You REALLY
DON'T want hosts to know about routing, even subnet routing!!
	
Bob Braden