Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!ucsd!brian
From: brian@ucsd.EDU (Brian Kantor)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: what is dynamic IP address assignment
Message-ID: <1181@ucsd.EDU>
Date: 13 Oct 88 14:35:18 GMT
References: <3921@Portia.Stanford.EDU> <2652@ditmela.oz>
Reply-To: brian@ucsd.edu (Brian Kantor)
Organization: The Avant-Garde of the Now, Ltd.
Lines: 25

In the ham radio tcp/ip world we're facing the need for dynamic address
assignment too.  Since the service is radio-linked, and people often
move, we have no central control over connection into our network.  Nor, 
I suspect, do we really want such.

The solution I've been toying with was to let the regional network
access nodes assign the addresses.  (Access by user stations/hosts to
the network is to be via dedicated network access nodes, similar in
concept to an IMP).  When a user station fires up in an area, he
requests assignment of an IP address (using some variant of RARP, I
suspect), and the local access node simply assigns the next one of its
allocated block of addresses to him.  The address is cached and will
be freed for reuse if no traffic is seen by that node from that station
for some reasonable period - like six months or so.

Since the underlying transport network (ham radio) has unique
identifiers (callsigns), this is a relatively straightforward way to
handle the problem.  I can see variations on the theme: that assignment
ALSO updates the distributed nameserver database; that there exists a
way to flush a station's entries from the address cache; etc.

With over 1500 hosts registered in over 20 countries so far, and more every 
day, we've got to find some way to automate the address assignment process.

	Brian Kantor	WB6CYT	UC San Diego   brian@ucsd.edu