Re: An idea: GxSE

["Paul Francis" <yoid2000@home.com>]

>
> TCP endpoint being associated with multiple addresses was
> discussed in draft-nikander-mobileip-homelessv6-01.txt.
> Isn't renumbering equivalent to a mobile node moving to
> a new foreign link ? In that case why can't renumbering
> event trigger all the TCP connections to generate a
> new secure message (known as binding update in mobile IPv6)
> to tell its peer about the new address ? After sending
> this message, TCP connections start using the new address.
> Why wouldn't this work ?

Strictly speaking it would work.  The need for secure messages makes it
expensive, as does the need to explicitly renumber hosts.

>
> If we are looking for a solution that would not change
> the end host's implementation, then the above is not
> suitable. So, is the requirement that the
> renumbering event should be completely transparent to
> the end hosts ?
>

GxSE obviously changes the host implementation (though there is a migration
path).

But yes, the requirement here is that the renumbering event be transparent
to end hosts (and also to internal routers).  I think this is important for
the same reasons that O'Dell expresses in GSE.  I think that sites will not
want to renumber, and will look for cheaper alternatives, of which there are
two:

1.  Convince the ISPs to advertise its prefix across the default-free
routing zone (i.e., what we do today with IPv4)
2.  Use NAT (also what we do with IPv4 today).

The goal of GxSE is to provide a solution that is about as easy as NAT, but
provides better functionality (mainly, connections survive in the face of
the site border routing crashing).

PF