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From: todd@janus.UUCP (Todd Booth)
Newsgroups: comp.unix.aix
Subject: IP routing subnet mask bug?
Keywords: routing subnet
Message-ID: <464@janus.UUCP>
Date: 19 Oct 89 17:04:39 GMT
Distribution: usa
Organization: Quotron Systems Inc., Los Angeles
Lines: 20

We have several logical networks on one physical network and are
having problems with IBM's PS/2 AIX V 1.1.  All networks have been
set up as class B (16 bits network and 16 bits host).  Of the 16 bits
host address, the AIX machines are using the first 10 as their subnet
address and the last 6 as their local host address.  

One problem is even though we set the subnet mask to 6 bits during
ifconfig, the IP routing logic seems to ignore this information.  We
can set up the route properly to other subnets via the local
interface, but applications can't find the route "unreachable".  Our
workaround to this is to route all "unreachable" IP packets via the
local interface (and hope) thats right.

The second problem is that machines on our subnet, for example,
130.224.4.1 see packets destined for other subnets, for example,
130.224.0.63.  I realize that in this case we have all 0's for
the subnet.  (Is there a way to configure AIX to ignore the *old*
style broadcast methods?)

--todd booth / Quotron