Re: someone is using my AS number

[Job Snijders <job () instituut net>]

On Thu, Jun 13, 2019 at 11:18 Warren Kumari <warren () kumari net> wrote:

> On Thu, Jun 13, 2019 at 9:59 AM Joe Abley <jabley () hopcount ca> wrote:
> > Hey Joe,
> >
> > On 12 Jun 2019, at 12:37, Joe Provo <nanog-post () rsuc gweep net> wrote:
> >
> > > On Wed, Jun 12, 2019 at 04:10:00PM +0000, David Guo via NANOG wrote:
> > > > Send abuse complaint to the upstreams
> > >
> > > ...and then name & shame publicly. AS-path forgery "for TE" was
> > > never a good idea. Sharing the affected prefix[es]/path[s] would
> > > be good.
> >
> > I realise lots of people dislike AS_PATH stuffing with other peoples' AS
> numbers and treat it as a form of hijacking.
> >
>
> Actually, I've been meaning to start a thread on this for a while.
>
> I have an anycast prefix - at one location I'm a customer of a
> customer of ISP_X &  ISP_Y & ISP_Z. Because ISP_X prefers customer
> routes, any time a packet touches ISP_X, it goes to this location,
> even though it is (severely) suboptimal -- things would be better if
> ISP_X didn't accept this route in this location.
>
> Now, the obvious answer of "well, just ask your provider in this
> location to not announce it to ISP_X. That's what communities / the
> telephone were invented for!" doesn't work for various (entirely
> non-technical) reasons...
>
> Other than doing path-poisoning can anyone think of a way to
> accomplish what I want? (modulo the "just become a direct customer
> instead of being a customer of a customer" or "disable that site", or
> "convince the AS upstream of you to deploy communities / filters").
> While icky, sometimes stuffing other people's AS in the path seems to
> be the only solution...



Given the prevalence of peerlock-style filters at the transit-free club,
poisoning the path may result in a large outage for your prefix rather than
a clever optimization. Poisoning paths is bad for all parties involved.

Kind regards,

Job