Re: intra-AS messaging for route leak prevention

[Hugo Slabbert <hugo () slabnet com>]

On Fri 2016-Jun-10 13:08:48 -0400, Christopher Morrow <morrowc.lists () gmail com> wrote:

> On Fri, Jun 10, 2016 at 1:05 PM, Mark Tinka <mark.tinka () seacom mu> wrote:
>
> > On 10/Jun/16 16:47, Christopher Morrow wrote:
> >
> >
> >
> > so I can't be a customer of you and a network you peer with?
> >
> >
> > You can, but we won't learn your paths via the peering session we would
> > have with your other ISP.

Wouldn't "learn but depref" be preferred and more common?  E.g. customer 
routes get tagged with "customer route" community and local-pref'd to 150 
or something; peer routes get tagged with "peer route" community and local 
pref'd somewhere below that.

Else any of your other customers that are single-homed to you can't reach 
your dual-homed customer A in cases where customer A's link to you is down, 
but customer A has other transits with whom you peer?

Unless it's mitigated by you accepting customer A's prefixes from any 
transits you have, which at the least seems sub-optimal (now reaching them 
via transit rather than peering if customer A's circuit is down) or 
possibly also up-ended if you also similarly apply "don't accept customer 
prefixes from transits".

No?

> >
> oh, so I didn't misunderstand.. that makes 'backup isp' less useful, no?

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Hugo Slabbert       | email, xmpp/jabber: hugo () slabnet com
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