RE: survivability, rewriting

["marcelo bagnulo" <mbagnulo@ing.uc3m.es>]

> > 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.
>
I am sorry, Erik, but i don't understand this argument.
Those rewritable addresses wouldn't be passed for referrals purposes, they
are just an artifact to let the M6 layer to notify the border router that
they should complete with a real prefix. The application would only be aware
of the AID. The referals would contain real locators. I guess i am missing
your point here :-(


> 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.
>

In what situation do you think that hierarchical rewriting would be needed?

I guess you are considering the small multi-homed provider that obtains
multiple prefixes, right?
Again, i don't believe this would be the way provider multi-homing will be


Regards, marcelo

>   Erik
>
>