From owner-freebsd-hackers  Thu Feb 15 14:15:42 1996
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To: Nate Williams <nate@sri.MT.net>
cc: "Garrett A. Wollman" <wollman@lcs.mit.edu>, hackers@FreeBSD.ORG
Subject: Re: Broadcast, Netmask, and other such information 
In-reply-to: Your message of "Thu, 15 Feb 1996 14:15:17 MST."
             <199602152115.OAA01407@rocky.sri.MT.net> 
From: David Greenman <davidg@Root.COM>
Reply-To: davidg@Root.COM
Date: Thu, 15 Feb 1996 14:15:29 -0800
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>Maybe I'm not making myself clear.  When I say 'addresses in the
>subnet', I'm trying to convey a number which *should* be a power of 2 #.
>In the above example, there are 32 addresses assigned in each subnet, of
>which there are only 31 usable as host addresses (except in the first
>and last subnets due to the .0 & .255 addresses being unusable).

   Actually, no, you would only get 30 hosts per subnet. The all-ones host
part on each subnet is the subnet's broadcast address and all-zeros host
can't be used, either.

-DG

David Greenman
Core Team/Principal Architect, The FreeBSD Project