Subject: RE: REMINDER: WG Last Call for "The Subnet Selection Option for D

From: "HIBBS, BARR (PB)" <[email-masked]>
Date: Mon, 26 Apr 1999 22:14:01 -0400 (EDT)

Ted, Thomas, Glenn, et al.--

Ted,

I wasn't sure if you were agreeing or disagreeing with Thomas about the need
for a subnet mask.  I don't agree that including the subnet mask necessarily
makes the server implementation more difficult, although I also don't think
it is really required:  as you point out, all current servers must somehow
do without the subnet mask when processing giaddr to determine the subnet
where the response is to be returned.

What is pretty clear to me is that if the subnet mask declared in the
server's configuration doesn't match the one provided by the client (if
Thomas' suggestion is adopted) at the very least there will be some
confusion, and at worst an address won't be served.  Having multiple sources
for the same information opens the possibility of contradictory
configurations which could introduce subtle operating problems.

--Barr

> ----------
> From: 	Ted Lemon[SMTP:[email-masked]]
> Sent: 	Monday, April 26, 1999 2:51 PM
> 
> > Finally, one other point. The option itself encodes a "subnet" as a
> > 4-byte field. Seems to me like you need to include the network
> > mask. One can't reliably extract a subnet number of an address just by
> > looking at it in the general case. 
> 
> That's what we do now!   This has to be dealt with by configuring the
> server to know the layout, including subnet masks, of the networks
> it's serving.   I don't think this adds value - in reality it's going
> to make the server's job harder, not easier, since the server will
> then have to implement a different code path to use the subnet
> selection option than it now uses to support the giaddr.
> 
>

---

From: Ted Lemon <[email-masked]>
Date: Tue, 27 Apr 1999 00:10:36 -0400 (EDT)

> for a subnet mask.

No, I was disagreeing strongly.   "I don't wanna hafta implement
that!"

			       _MelloN_