Re: GSE IDs [Re: IETF multihoming powder: just add IPv6 and stir]

[Iljitsch van Beijnum <iljitsch@muada.com>]

On vrijdag, mei 9, 2003, at 14:05 Europe/Amsterdam, Bound, Jim wrote:

> By storing the end nodes in a routing header all other location can
> change enroute.
> This is completely stateless.
Not really. Someone must know to put in the routing header at some 
point.

And this doesn't provide the functionality we need. Assume ISP A can 
reach destination X but ISP B can't. In this case, the source must 
transmit the packet over A. Transmitting it over B isn't going to yield 
useful results, regardless of the presence of routing headers.

Also, we can't assume that users will universally prefer a stateless 
solution with per-packet overhead over a stateful one that doesn't have 
extra overhead.

I think state in the endpoints is perfectly acceptable. If people want 
central control over their multihoming and/or they want to 
multihome-enable unmodified hosts by implementing the multihoming 
functionality in a middlebox, having state in this middlebox would also 
be acceptable, especially if it's "soft state" that can be recreated 
without breaking sessions if the middlebox fails. NAT shows that it is 
possible to build middleboxes that keep lots of state.