Re: prefix filtering per IRR - practices

[Michael Hallgren <m.hallgren () free fr>]

Le 22/11/2013 17:57, Chris Rogers a écrit :
> From my experience, networks that are capable of filtering from IRR objects
> generally filter for exact routes, meaning no "le 24". 

Hi,

Are you sure? My experience is, with a small number of exceptions,
that "le 24" ('route' or 'route-set,' sometimes in relation with "is in
AS-set of peer") is an often used policy. Maybe it depends on what
kind of networks one's looking at? 

Cheers,
mh

> While I've always
> found networks to be set in their ways, I know some people that have
> managed to get their filters changed to allow longer prefixes without
> needing additional objects.
>
> But ultimately, it does help prevent the leaking of internal routes.
>
> -Chris
>
> On Fri, Nov 22, 2013 at 6:55 AM, Frank Habicht <geier () geier ne tz> wrote:
>
> > Hi,
> >
> > I have a question regarding what's the most common practice [1]
> > for transit ASs to filter prefixes from their BGP customers
> > when using IRR data. (which of course everyone does...)
> >
> > Would many/most/all/none :
> > a) accept only the prefixes listed in route objects
> > or
> > b) accept these and anything "upto /24" (or "le 24")
> >
> > I was hoping / assuming the latter but I start getting a different
> > impression.
> > Yep, and apart from the current status, the tendency would be of interest.
> >
> > Thanks,
> > Frank
> >
> > [1] after "my network, my rules"