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From: leinwand@hpccc.HP.COM (Allan Leinwand)
Newsgroups: comp.dcom.sys.cisco
Subject: Re: Serial interfaces IP number question
Message-ID: <14050006@hpccc.HP.COM>
Date: 21 Aug 90 20:11:19 GMT
References: <2442@s3.ireq.hydro.qc.ca>
Organization: HP Corp Computing & Services
Lines: 23

> / hpccc:comp.dcom.sys.cisco / RAF@CU.NIH.GOV (Roger Fajman) /  9:23 pm  Aug 20, 1990 /
> We did that, but it didn't work out very well in practice.  The problem
> is that the subnet mask exists in so many places (routers and hosts)
> that people get very upset when you want to change it.  So we finally
> settled on a 7 bit subnet mask and got a second class B address to use
> when we run out of subnets.  That probably will be next year sometime.
> We will have to assign a subnet address from each net number to our
> backbone networks in order to keep the subnets of each net contiguous.
> ----------

   Yes, changing a subnet mask on every system within a network can be
very difficult.  On our network, even changing a subnet mask on all the routers
would be quite a task.

   I still think the best bet is to plan the network correctly and get the
appropriate network number assigned in the beginning.

Thanks,

Allan
allan@hpcta.corp.hp.com
Hewlett-Packard
Network Solutions Engineering