Re: using IRR tools for BGP route filtering

[John Fraizer <nanog () EnterZone Net>]

I agree totally with prefix-list filtering customers and we have done so
from the very beginning.  (Who wants to blemish the reputation of their
ASN as result of a customer being a bonehead and announcing default, etc?)
Provider<->Provider prefix-list filtering becomes much more involved
however.  When a provider has 400+ bilateral peering relationships, the
time it takes to bring a new customer online who has their own address
space grows substantially.  It is no different when a provider obtains
additional address space.  If their peers are prefix-list filtering, they
have to contact every peer to have them blast a hole in the filters for
the new address block.

In a perfect world, we would not need to filter, period.  Filtering
customers has become necessary to survival.  I see Provider<->Provider
filtering as a major hurdle to jump anytime your (or anyone elses) network
expands in relation to prefixes being legitimately announced.


---
John Fraizer
EnterZone, Inc


On Thu, 22 Jun 2000, Danny McPherson wrote:

> I agree with this, and have seen the document, and have worked for 
> large providers that performed prefix filtering on customers long
> before IOPS existed.  
>
> However, if every ISP performed prefix-based filtering between one 
> another, it'd be improved "a lot more".  I recall more than a few 
> instances when providers inadvertently broke other providers customers 
> by "mis-advertising" prefixes.  
>
> And if every ISP performed SA verification between one another 
> (presumably with the same filters) it would again be improved "a 
> lot" more.
>
> -danny
>
> > If every ISP does prefix based filtering on its
> > downstream customers, the integrity of the Internet
> > routing system will be improved a lot. The document
> > below proposes such a model:
> >
> > http://www.iops.org/Documents/routing.html