Subject: RE: Identification

From: "Bound, Jim" <[email-masked]>
Date: Mon, 17 Mar 2003 03:06:01 -0500

I agree.  But can we make them global?  I think so.  Ted Lemon fought
this battle in DHCPv6 and there may be a precedent there at least it had
consensus in that forum/WG.  And we did come up with these really far
fetched ways of breaking Teds postulate but it was silliness to even
worry about it.  Nothing will be perfect.
Good point about Z +  Port to find TCB.  It must be possible I think.
But my fridge should be able to update its identifier I think.
 
OK time to sleep.
 
/jim

	-----Original Message-----
	From: Tony Li [mailto:[email-masked]] 
	Sent: Monday, March 17, 2003 2:57 AM
	To: David Conrad; Bound, Jim
	Cc: [email-masked]
	Subject: RE: Identification

	I agree with most of what David said, except for this.  I
interpret Jim's comment as asking
	if the identifier is local to a particular location.  In other
words, it acts as the low order bits
	of the 'address'.  The issue with this is that it makes absolute
identification a bit more
	challenging.  For example, suppose that A, B, C, ... are
locators and we have identifier Z.
	 
	A.Z and B.Z just happen to be the same host because it's
multihomed, but then C.Z is another
	host entirely.  What happens?  It means that hosts can no longer
key on 'Z', and then have to
	have other mechanisms so that they can determine that A.Z and
B.Z are the same host, both
	at an insecure and secure level.
	 
	If Z is instead global, then I believe that the identification
problem is a bit simpler.  Consider the
	role of looking up the TCB in your TCP implementation.  You just
index by Z and ports and you're
	done.  No futzing around trying to figure out if A.Z and B.Z are
the right thing.
	 
	For this reason, I would tend to favor making identifiers
global.  I think it's just simpler.
	However, the other way probably CAN be made to work with enough
effort.  In my mind, this
	is one of the microarchitectural pieces that we don't need to
argue about now.
	 
	Tony

		 Can identifiers be within the context of Location? 

		Not sure what this means. Reachability to a given
identifier depends on its locator, so perhaps I'd say yes.