Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!decwrl!decvax!ucbvax!A.ISI.EDU!CERF
From: CERF@A.ISI.EDU
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Exchanging serial numbers
Message-ID: <[A.ISI.EDU]27-Feb-88.09:04:07.CERF>
Date: 27 Feb 88 14:04:00 GMT
References: <8802251906.AA04676@wb6rqn.UUCP>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 20

If you plan to break if you get the same serial number as you sent,
you will fail to provide service to processes that call themselves.
The TCP protocol specifically allows this (supports it as a
simultaneous initiation of connection case). The idea is to allow
processes, whereever situated, to use the TCP/IP as a way of communicating.
It sounds to me as if your serial number checking plan will break
that feature...

Vint

P.S. I just realized that your plan would break communications
between distinct processes in the same host should they try
to communicate via TCP/IP. In applications for which software
is moved from one place to another during or prior to execution,
a process might well call another in the same host without 
realizing it. Furthermore, you might want that feature so as to
avoid having to do something special to distinguish inter-host
and intra-host communication.

Vint