Cameron, We only have one upstream which does not filter and we have filtered since day zero. The upstream who does not filter originally did filter us, but removed filtering specifically for our asn as they had an issue with their filter management code that wouldn't accept certain AS paths and due to their size and the time it would take to fix being too long, it was easier to jump through some compliance hoops with them than for them to keep filtering. I would in my experience, even with Large US Tier 1's not say that filtering is the exception at all. Kind Regards, David Hooton Managing Director Platform Networks www.platformnetworks.net Ethernet Over Copper coverage in over 2000 exchanges nationally - Ask me about it! ----- Original Message ----- From: Cameron Kerr [mailto:ckerr(a)cs.otago.ac.nz] Sent: Wednesday, March 02, 2011 08:30 AM To: nznog <nznog(a)list.waikato.ac.nz> Subject: [nznog] How common is unfiltered BGP? Hi everyone, I'm just updating my lecture on exteriour routing for this year, and am wanting to know more about the current state of unfiltered BGP, whereby a customer can advertise a prefix they don't have, their service provider didn't suitably filter the advertisement, and it disrupts other networks in the internet. My previous impression, based on discussions around incidents such as the YouTube/Pakistan incident, lead to me believe "Most people don't filter", and I'm just wanting to see if that is [still] the case now. (Also, thanks to Andy for the NRO nudge) Cheers, Cameron _______________________________________________ NZNOG mailing list NZNOG(a)list.waikato.ac.nz http://list.waikato.ac.nz/mailman/listinfo/nznog