nanog mailing list archives
BGP Filtering
From: "Ben Butler" <ben.butler () c2internet net>
Date: Tue, 15 Jan 2008 16:11:36 -0000
Hi, Considering: http://thyme.apnic.net Total number of prefixes smaller than registry allocations: 113220 !!!!! /20:17046 /21:16106 /22:20178 /23:21229 /24:126450 That is saying to me that a significant number of these smaller prefixes are due to de-aggregation of PA and not PI announcements. My question is - how can I construct a filter / route map that will filter out any more specific prefixes where a less specific one exists in the BGP table. If my above conclusion is correct a significant portion ~47% of the number of the prefixes in the table could be argued to be very unnecessary at one level or another. Is such a filter possible easily or would it have to be explicitly declared, any chance of a process the automatically tracks and publishes a list of offending specifics similar to Team Cymru's Bogon BGP feed. As a transit consumer - why would I want to carry all this cr*p in my routing table, I would still be getting a BGP route to the larger prefix anyway - let my transit feeds sort out which route they use & traffic engineering. Thoughts anyone? Kind Regards Ben
Current thread:
- BGP Filtering Ben Butler (Jan 15)
- Re: BGP Filtering Jared Mauch (Jan 15)
- RE: BGP Filtering Ben Butler (Jan 15)
- Re: BGP Filtering Joe Abley (Jan 15)
- RE: BGP Filtering Ben Butler (Jan 15)
- Re: BGP Filtering Dave Israel (Jan 15)
- RE: BGP Filtering Ben Butler (Jan 15)
- Re: BGP Filtering Dave Israel (Jan 15)
- Re: BGP Filtering William Herrin (Jan 15)
- Re: BGP Filtering Dave Israel (Jan 15)
- RE: BGP Filtering Ben Butler (Jan 15)
- Re: BGP Filtering Jared Mauch (Jan 15)
- Re: BGP Filtering Deepak Jain (Jan 15)