Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cwjcc!gatech!galbp!wittsend.lbp.harris.com!mhw
From: mhw@wittsend.lbp.harris.com (Michael H. Warfield (Mike))
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Subnet 0
Message-ID: <8721@galbp.LBP.HARRIS.COM>
Date: 20 Sep 89 21:42:30 GMT
References: <41@cvbnet.Prime.COM> <8909151911.AA14633@uf.msc.umn.edu>
Sender: news@galbp.LBP.HARRIS.COM
Reply-To: mhw@wittsend.UUCP (Michael H. Warfield (Mike))
Organization: Lanier Network Knitting Circle - Thaumaturgy & Speculums Division
Lines: 30

In article <8909151911.AA14633@uf.msc.umn.edu> fin@UF.MSC.UMN.EDU ("Craig Finseth") writes:

>	Is is "allowed" (i.e., technically legal)?

>Undefined.  Network number 0 means "this net."  By analogy subnet
>number 0 means "this subnet."  You won't find this mentioned anywhere
>official, that's why it is undefined.

	This was discussed some time ago in this news group and it was
generally agreed that subnet 0 was prohibitted by RFC 950.

	Subnet 0 is mentioned in RFC950 as follows:

+-------------------------RFC 950 ---------------------------------------+

         It is useful to preserve and extend the interpretation of these
         special addresses in subnetted networks.  This means the values
         of all zeros and all ones in the subnet field should not be
         assigned to actual (physical) subnets.

+-------------------------RFC 950 ---------------------------------------+

	It will work in most cases (I know, I'm running one; sigh).  However,
it is not a good ideas, it should be avoided, and it is technically proscribed.


Michael H. Warfield  (The Mad Wizard)	| gatech.edu!galbp!wittsend!mhw
  (404)  270-2123 / 270-2098		| mhw@wittsend.LBP.HARRIS.COM
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