[routing-wg] Bogon ASN Filter Policy

On 02/06/16 21:43, Job Snijders wrote:
> After the Bogon ASN filter policy has been deployed, AS 2914 will not
> accept route announcements from any eBGP neighbor which contains a Bogon
> ASN anywhere in the AS_PATH or its atomic aggregate attribute.

Hi,

I have no problem with filtering Bogon ASNs from the AS_PATH.

However, I do want to mention that filtering route announcements with
Bogon ASNs in the AGGREGATOR attribute will result in dropping the
current RIS Routing Beacon announcements.

They overload the AGGREGATOR attribute with extra information to encode
the time of the announcement, a sequence number, and the originating
RRC, into the AGGREGATOR using private ASNs. The schema is documented here:
https://www.ripe.net/analyse/internet-measurements/routing-information-service-ris/current-ris-routing-beacons


This information has been used in many studies into prefix propagation
and convergence, flap dampening, etc.

If there is a desire to block the propagation of routes with these
attributes, we will need to investigate alternatives to the current
beacon encoding.

We are, of course, happy to consider any community input into how this
should be handled.

Kind Regards,
Colin </hat="RIS">

--
Colin Petrie
Systems Engineer
RIPE NCC