Re: [lir-wg] Discussion about RIPE-261
- Date: Wed, 28 May 2003 14:24:02 +0100
- Organization: PT Comunicacoes - Marconi
On Wed, May 28, 2003 at 01:07:08PM +0200, Gert Doering wrote:
> Hi,
>
> On Wed, May 28, 2003 at 10:45:44AM +0100, Carlos Morgado wrote:
> > On Tue, May 27, 2003 at 09:07:05PM +0200, Gert Doering wrote:
> >
> > > The *benefit* of "/48 multihoming" is that you can filter those routes
> > > if you don't want to see them - then your routers will send packets
> > > down the /32 road, and eventually hit a router that knows about the /48
> >
> > This is exactly why providers will have an hard time selling this to
> > customers. 'It may work, it might not, depends, you have no control and
> > neither do we'.
>
> One of us us confused about this, and it's not me.
>
> A /48 from an aggregate is MUCH MORE reliable than a /48 that has no
> fallback aggregate. If the latter is filtered (or flap-dampened, or
> "lost" due to bad as-path filters, or however), you're dead. If the
> former is lost, you can always send packets in the direction of the
> aggregate, and at a certain proximity, the /48 will be visible again
> and be used for proper packet delivery.
>
Ok, I wasn't clear - I was strictly speaking about broken up PA space, not
PA /48 vs. PI /48.
You're right, if people per rule filter at /32 PI /48 is worse. If
people per rule filter at /48 (which seems to be a requirement for this
scheme to work) then /48 PI is better as it permits traffic engineering
by the multihomed network.
I mean, if you multihome and know for a fact at least half of the internet
won't see one of your links (either because of filters or sumarization)
what's the point ?
If you do know /48s will indeed be visible by most of the internet using
PI results in the same number of entries as PA, allows better control
by the multihomed network and given a carefull allocation policy (now that
IPv6 space is plenty and sparse) allows to grow the /48(s) into bigger
allocations with minimal disruption.
> Besides this, I hope you're not selling *any* service related to Internet
> connectivity to your customers with the claim that you have any control
> about things more than two AS hops away from your network...? Because
> you haven't.
>
No, I'm selling in technical good faith. I currently take steps to
maximize the quality of the transit I sell considering the current
IPv4 framework and current practices. In my opinion however with
the /48 PA method I can't in good faith sell the same level of service.
cheers
--
Carlos Morgado chbm@localhost - Internet Engineering - Phone +351 214146594
GPG key: 0x75E451E2 FP: B98B 222B F276 18C0 266B 599D 93A1 A3FB 75E4 51E2
The views expressed above do not bind my employer.
