Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!uunet!ns-mx!jay.weeg.uiowa.edu!jnford
From: jnford@jay.weeg.uiowa.edu (Jay Ford)
Newsgroups: comp.protocols.tcp-ip
Subject: multiple subnet masks on same net
Keywords: subnet, routing
Message-ID: <1951@ns-mx.uiowa.edu>
Date: 25 Jul 90 19:06:45 GMT
Sender: news@ns-mx.uiowa.edu
Reply-To: jnford@jay.weeg.uiowa.edu (Jay Ford)
Organization: Weeg Computing Center, University of Iowa, Iowa City, IA, USA
Lines: 21

We currently have a class-B number (128.255) with 8-bit subnetting (mask
255.255.255.0).  Some folks on our campus net have an interest in subdividing a
subnet into a bunch of 11-bit sub-subnets (mask 255.255.255.224).  The
sub-subnets will each contain a small number of systems (< 32), so full 8-bit
subnets would be sparsely used.

This probably requires a router which has interfaces with different masks, one
with 255.255.255.0 and one with 255.255.255.224.  We'd like to use a BSD system
as a router.  I don't think routed (the BSD RIP implementation) will deal with
the inconsistent masks, and it doesn't seem that gated likes them very well
either.

I'd appreciate some advice from anyone who's done this sort of thing.  It seems
like a fairly reasonable way to better utilize the address space, but the
standard software doesn't appear to support it.

Thanks.


Jay Ford,  Weeg Computing Center,  University of Iowa,  Iowa City,  IA  52242
jnford@jay.weeg.uiowa.edu  or  jnfordpb@uiamvs.bitnet,  319-335-5555