Re: comments on mipv6 application to multihoming [Re: Move forward]

[Pekka Savola <pekkas@netcore.fi>]

On 19 Mar 2003, marcelo bagnulo wrote:
> I am running out of solutions here :-)
> I can think of the following options for this, but i am not sure i like
> anyone of them.
> 
> First option: (i think this would be the most elegant, but i think its
> time has passed) use a site local anycast address
> So you can compose the site exit router anycast address by appending the
> prefix assigned to the link to the site local prefix. I like this, but
> the problem is that there may be no more site locals for connected
> sites. I guess i should wait and see the outcome of the site local
> debate.
> 
> Second option: use the above configuration and configure R3 as a ND
> proxy. I do not like this much because it imposes additional
> configuration in all the routers (it is better than configuring all the
> hosts, though)
> 
> Third option: (nasty hack) use the above configuration but change the
> site exit router anycast format by changing the less significant bit of
> the directly attached subnet. This would make that the anycast address
> is not on-link, so that it has to be routed through a router. 

1) is out of question, 2) seems undesirable but acceptable, 3) too hacky.

A possibly valid approach could be advertising the addresses or portions
of significant information thereof (e.g. prefix length and have a reserved
anycast address) in route advertisements.

But I don't really like this approach either.

A discovery approach would also be possible: e.g. send traceroutes using
all the source addresses and watch out for responses (assuming there is
some special "site exit router discovery" ICMP message).

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings