Re: survivability, rewriting

[Erik Nordmark <Erik.Nordmark@sun.com>]

> About the rewriting: why again are we making life difficult for 
> ourselves? The obvious place to put an indication that the address may 
> be rewritten is... in the address. Is there any reason why we can't 
> have one or more special prefixes that indicate that a router should 
> fill in the source address?

Two answers:
1. The ULPs need to know the addresses of the node itself to be able
   to perform certain forms of referal. But that doesn't prevent
   the node to issue IP packets with a source locator that doesn't
   include the upper bits of the address *as long as* the host knows
   that there is a rewriting router along the path.

2. Having a designated prefix in the source locator to indicate "rewrite ok"
   prevents hiearchical rewriting; this is when e.g. your border router 
   rewrites the prefix and your ISPs border towards its upstream can also 
   rewrite.

  Erik