Re: draft-kurtis-multihoming-longprefix comments

[Kurt Erik Lindqvist <kurtis@kurtis.pp.se>]

> > There is two sides to this
> > a) Why do people multihome?
> > b) Why do they want PI-like address space?
> > What worries me is if people are doing a to get to b. I don't want to
> > see these two being the same.
> People multihome because it makes their connection to the net more
> reliable, because it is sometimes cheaper and because you get better
> performance if interconnection between ISPs isn't very good.
>
> People want PI space because that way changing ISPs is trivial. And 
> even
> for people who don't want to multihome this is very important: if your
> ISP goes belly up, you want to be able to connect to a new one very
> quickly.
Well, this is what I intuitively would say as well. However, there is 
(as you yourself noted in an earlier email) not that many people that 
multihome. There are a lot more that get PI space. I am still doubtful 
that we understand the issue.

I am leaning to the conclusion that what you want depend on what you 
are. And each will require a different solution.

In principle, a "advanced" DSL home user want to multihome for price. 
Here are multiple address solution might be the right answer.

If I am a SOHO, I am probably also after cost benefits.

If I am a on-line broker I am probably after resilience, and a routing 
solution might be what I want.

If I am IBM, I will fall under any provider category.

I think something that is very important to keep in mind is what Tony 
Li said, we need to get away from the model where when a user want's to 
multihome he will add a entry in the DFZ. The question is, does that 
apply for everyone and do we think we can get there in one single large 
evolutionary step?

I think we need to get there; we will get there; but we will have to do 
it bit by bit.


> In theory, renumbering isn't a big problem: you only need to change a
> DHCP configuration or some prefix advertisements. In practice, it is a
> nightmare because IP addresses show up in way too many places, often to
> enforce access restrictions. Getting rid of this is probably the 
> hardest
> part in any multiple-address solution.
I know of some really large re-numberings. I think most of the time, 
people are making a larger fuss of this than it is.


Best regards,

- kurtis -