more specific routes in today reality

Hi,

On Tue, Oct 09, 2001 at 04:38:36PM -0400, Lu, Ping wrote:
> > On Tue, Oct 09, 2001 at 09:13:05PM +0200, Jan-Ahrent-Czmok wrote:
> > > Some providers are multihomed
> > > but cannot cover the costs, even for a small lir.
> > 
> > If you want to be multihomed, the costs for routers & co. are 
> > far higher
> > than for being LIR.  If you can't afford being LIR, be single-homed.
> > 
> 
> Great! Now we have to collect routing policies from thousands of small LIRs
> while still have to deal with thousands of small prefixes.

So?  There is no difference between thousands of PI prefixes and 
"thousands of small LIRs", except that the latter actually have to
*pay* for what they cause.

[..]
> > Please do your homework about routing and BGP before selling people 
> > consulting about multihoming.
> 
> Now more and more major ISPs are filtering out routes from other ISPs (
> becuase we don't have
> transit agreements) so the multi-homed customer have to have their own AS.

No.  This is an interesting arguments, but the fact that C&W has problems
with some of their peers doesn't mean "the whole world has to drown in
multihomed ASes".  Get your contracts right.

> And if the major ISPs stop listening to the more specfic routes then even
> using the address from PI space won't work (unless you are big enough).

Yes.  This is what it's all about.  Small PI space really hurts people.

> All these solutions kind of imply that if you can't have /20 prefix then you
> can't be multi-homed. What happen if a customer want to have an OC-48
> multi-homed link but only use prefix < /20 (that happens to the Internet
> Exchange people a lot ) ? 

So announce it to the internet exchange.  Why does it have to be visible
in the whole world?

Letting "the whole world" see a /16 (from the upstream) and the direct
peers a /24 (or whatever) means global routing will just work fine (over
the upstream's PA block) and and IX routing will also work just fine
(using the more specific).

Bad example.

Gert Doering
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