nanog mailing list archives
Re: BGP prefix filter list
From: Robert Blayzor <rblayzor.bulk () inoc net>
Date: Thu, 30 May 2019 13:43:40 -0400
On 5/30/19 12:54 PM, William Herrin wrote:
It's permissible to announce to your transits with a private AS which they remove before passing the announcement to the wider Internet. As a result, the announcement from each provider will have that provider's origin AS when you see it even though it's actually from a downstream multihomed customer.
If you were a multi-homed customer the route would still originate from two different AS's, both of your upstream ISP's. If it's the same ISP, then that would not apply. But then again, if it were the same ISP they could filter the more specific and learn downstream customer routes either by IGP, filtering or tagging the /24 with no-export. -- inoc.net!rblayzor XMPP: rblayzor.AT.inoc.net PGP: https://pgp.inoc.net/rblayzor/
Current thread:
- Re: BGP prefix filter list, (continued)
- Re: BGP prefix filter list William Herrin (May 30)
- Re: BGP prefix filter list Mel Beckman (May 30)
- Re: BGP prefix filter list Thomas Bellman (May 30)
- Re: BGP prefix filter list Mel Beckman (May 30)
- Re: BGP prefix filter list Valdis Klētnieks (May 30)
- Re: BGP prefix filter list Mel Beckman (May 30)
- Re: BGP prefix filter list Thomas Bellman (May 31)
- Re: BGP prefix filter list Valdis Klētnieks (May 30)
- Re: BGP prefix filter list Matt Corallo (May 30)
- Re: BGP prefix filter list Saku Ytti (May 30)
- Re: BGP prefix filter list Robert Blayzor (May 30)
- Re: BGP prefix filter list William Herrin (May 30)
- Re: BGP prefix filter list Robert Blayzor (May 30)
- Re: BGP prefix filter list Robert Blayzor (May 30)
- Re: BGP prefix filter list Brielle (May 15)
- Re: BGP prefix filter list Jon Lewis (May 15)
- Re: BGP prefix filter list Dovid Bender (May 15)
- Re: BGP prefix filter list Mike (May 15)
- Re: BGP prefix filter list Mark Tinka (May 16)