Path: utzoo!yunexus!davecb
From: davecb@yunexus.UUCP (David Collier-Brown)
Newsgroups: can.uucp
Subject: What happens when a subdomain (actually a machine) moves?
Message-ID: <2488@yunexus.UUCP>
Date: 29 Jun 89 15:08:40 GMT
Article-I.D.: yunexus.2488
Distribution: can
Organization: York U. Computing Services
Lines: 36


   We just had an interesting question come up: a machine (not
a person) in a subdomain nearby just moved to a different 
subdomain.
	ie, machine.org1.foo became machine.org2.foo

   If this were snail-mail, I'd know exactly what it should do: send
the postmaster a postcard saying "I moved" and then send postcards to
all its correspondents.
   But that assumes a single postoffice that can unambiguously change
the org1 to org2 on all incoming mail. (For a fee (:-)).  In the email
universe we have numerous non-identical, sorta-replicated-almost
postoffices which are historical artifacts of the fact that there
are distinct physical networks...

   Eventually, all the postoffices will become aware of and consistent
with the domain addressing scheme we've imposed on them.  Then the
procedure will appear as simple as the snailmail case.  But right now
we aren't quite that rational. And I confess that its probably harder
to change N postoffices manually than to make them "behave"
algorithmically.

   So what should the wandering machine do?  Try to negotiate N
changes, one for each historical net? (N may be **large**) Wait for
them to converge?  Pretend to be both places until it stops getting
mail sent to the wrong place?  Or none of the above?

 --dave (surely someone's experienced this before...) c-b



-- 
David Collier-Brown,  | davecb@yunexus, ...!yunexus!davecb or
72 Abitibi Ave.,      | {toronto area...}lethe!dave 
Willowdale, Ontario,  | Joyce C-B:
CANADA. 223-8968      |    He's so smart he's dumb.