prefix filtering per IRR - practices

Chris Rogers crogers at
Fri Nov 22 16:57:04 UTC 2013

>From my experience, networks that are capable of filtering from IRR objects
generally filter for exact routes, meaning no "le 24". 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.


On Fri, Nov 22, 2013 at 6:55 AM, Frank Habicht <geier at> 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"

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