Re: Shim6 proxies

[Scott Leibrand <sleibrand@internap.com>]

On 04/20/06 at 4:02pm +0300, marcelo bagnulo braun <marcelo@it.uc3m.es> wrote:

> you can still make source address based routing work in multiple hops
> or you can use a mesh of tunnels to allow exit routers to forward the
> packet to the proper exit router and so on...

If this is a requirement to implement shim6, it will not happen.  It
doesn't scale, and is way too complicated to manage.  Either we find a way
to automate source routing by IGPs, or we give up on letting hosts control
its egress in networks with more than one broadcast domain.

> but, i guess that as the site grows, such approaches may collide with
> other requirements

I don't think it requires any growth to get such collision.  I'll put it
even more bluntly: almost anyone with enough routers to have an IGP and
run BGP *will not* want to multihome with shim6 as currently specified.
They may be fine with enabling shim6 on their hosts so they can talk with
multihomed hosts at smaller sites, but for their own multihoming such
sites will want to use traditional BGP techniques.

As I've said before, I think the shim6 design needs to recognize that it
will not be the One and Only method for multihoming, and therefore it
needs to be designed to ensure that hosts that don't use shim6 for
multihoming can still interoperate with multihomed hosts and small sites
that do want to use shim6.

-Scott