Re: The state of IPv6 multihoming development

[Iljitsch van Beijnum <iljitsch@muada.com>]

On Mon, 28 Oct 2002, Pekka Nikander wrote:

> > Hm, what problem exactly does this solve that isn't solved by (for
> > instance) SSL?

> That is a subtle question, thanks for asking that.  That is also
> exactly the question which has prevented HIP from becoming a WG
> a long time ago.  I think that the multi6 list is perhaps not the
> right place to discuss that question, the answer is too long.

If the answer is so long, how do you expect to convince people they need
it...?

> If you are interested, let's move this point off-line, to
> the HIP mailing list, or some other better suited mailing list.
> And please read the NSRG report before we start to dive into this.

Ok.

> > Also, how does the hash to IP address mapping work in the absence of a
> > hierarchy?

> How does a name to IP address mapping work today?  Using DNS,
> for example.  Or some other name resolution service.

The DNS is strictly hierarchical. If address/number/hash 1234::5678
belongs to organization A, 1234::5679 to B, 1234::567A to C and so on,
it is impossible to delegate authority so the whole thing must be
administered at some central place. This is bad. This problem is one of
the reasons why GSE didn't make it.

> I agree.  Basically I wanted to point of the following:

>   1. Once we start to discuss solutions that require changes to the
>      end host (and perhaps these "mudem"s), there is also the option
>      of introducing a new name space, cryptographic or not.

I don't completely agree (or disagree). Yes, the best time to do this
would be when making changes anyway, but since this means changing more
than what's needed to get multi-address multihoming going, doing it at
the same time isn't "free".

>   2. End-host based multi-homing solutions *seem* to have the
>      same security problems as (some) end-host mobility solutions.

That's what everyone has been saying the last few days. However, I see
some fundamental differences. First of all, in multihoming all the
addresses are known beforehand. This gives us more options to implement
security mechanisms. Second, mobile hosts are likely to travel to a
place where the network is less secure than at their home location. For
multihomed hosts, the security of their network connections doesn't
really change.

> If you create a solution where identifiers are simply
> routable addresses, you are, from my point of view, basically
> re-inventing Mobile IPv6.  And since there are so many
> problems with Mobile IPv6, I am quite sceptical about such
> a design.  Well, Mobile IPv6 works (probably) and the security
> problems have been solved, but the result is, well, large
> and complex.  But perhaps I'm short sighted here, and you
> have something else in your mind.

As you say, MIPv6 is complex. I haven't fully digested how this works,
so it's hard for me to say much about it. I realize that there is a lot
of overlap in what needs to happen, but the functionality is
fundamentally different so I don't think we are reinventing the same
thing.

Iljitsch