Re: Transport level multihoming

[Ran Atkinson <rja@extremenetworks.com>]

At 13:33 03/04/01, Brian E Carpenter wrote:
>I'm against making that too absolute. It is a bit more subtle:
>
>  A multihomed site must be able to operate legacy applications
>  unchanged. However, it may be desirable for the multihoming
>  system to offer hints or even controls to applications able
>  to use them, by means of a multihoming API.

        I'd edit that to clarify what is meant by "...to 
operate...unchanged".  That phrase could mean operate legacy 
apps without multihoming capability without change xor it could
mean operate legacy apps with multihoming capability unchanged.

>A more basic question - are we able to *require* changes in the
>host IPv6 stack in support of multihoming? 

        If not, then we close the door on a large class
of potential solutions.  In particular, the TCP/UDP
Protocol Control Blocks currently bind the IP addresses 
on both sides tightly into each session.  The sort of approach
that GSE outlined would want to bind the PCBs to some
identifier that was not the IP address used for packet
forwarding.

Ran