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Date: Mon, 05 Apr 2004 15:41:28 +0200
From: Andre Oppermann <andre@freebsd.org>
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To: Anders Lowinger <anders.lowinger@packetfront.com>
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cc: Luigi Rizzo <rizzo@icir.org>
cc: net@freebsd.org
Subject: Re: do we support non contiguous netmasks ?
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Anders Lowinger wrote:
> 
> Luigi Rizzo wrote:
> > Hi,
> > i was wondering if anyone knows what kind of support we have
> > in FreeBSD networking code, for non contiguous netmasks.
> > While it is trivial to support them for interface addresses,
> > managing them in the routing table is probably far from trivial
> > and I believe also mostly useless... and anyways, i have no
> > idea how our kernel code deals with them
> 
> Not sure why you wonder? Do you need it?
> 
> If we implement a mtrie for faster routing-lookups,
> non-contiguous masks need to go.
> 
> Not even Cisco implements anything else than contiguous masks,
> and I have a very hard time to understand why they are needed.

So far I haven't found any useful application of non-contignous
mask in network applications.  It can probably go away.  But step
by step.  Currently Luigi has teamed up with me to do the per-if
ARP table stuff and the removal of cloning from the routing table.
That alone will make network life in the kernel much easier.

-- 
Andre