Subject: Re: host address zero - useable?
To: Andrew Brown <atatat@atatdot.net>
From: Erik E. Fair <fair@clock.org>
List: tech-net
Date: 03/09/1999 20:43:04
At 20:21 -0800 3/9/99, Andrew Brown wrote:

>uh...well...not really.  for example, if i had 192.1.0.0/23 assigned
>to my network, i could use 192.1.1.0 as a host address.  parts of the
>internet might not be "happy" with it, but it's certainly legal.

I guess I'm not being clear. For any given network & network mask (e.g.
192.1.1.0/24), when the *host* part is *all* zero bits (i.e. 192.1.1.0),
NetBSD generates a MAC-level broadcast for packets sent to that address. It
also does this for the all ones host address (i.e. 192.1.1.255).

I have no problem with one IP address being reserved for broadcast. Two is
excessive. We should fix this in our OS. I need to go re-read RFC-1122
about this issue.

	Erik