nanog mailing list archives
Re: /24's run amuck?
From: James Aldridge <jhma () mcvax org>
Date: Wed, 07 Feb 2001 15:56:38 +0000
Valdis.Kletnieks () vt edu wrote:
And now for the *tough* question - of those 58K /24's, how many could be eliminated by more careful aggregation and filtering? I'm willing to bet that at least 25% are sites that have two connections to their provider, and are therefore advertised within the provider's net, and are simply escaping due to misconfiguration at the border. So - who wants to crunch the numbers and figure out how many of those 58K are useless punchouts ("Route all of 128.257.x.x to me, except for 128.257.219.x, which also goes to me").... Bonus points for identifying the AS that covers the greatest percentage of its address space with aggregable punchouts (although I'm willing to bet that there's some offenders out there with greater than 100% ;)
You might want to take a look at the aggregation possibilities I've been finding at http://www.mcvax.org/~jhma/routing/ (everything there is updated on a daily basis). Based purely on origin AS, for any AS where any form of aggregation could occur, it lists which new aggregates should be announced (in place of individual specific routes), and which should be withdrawn (your "useless punchout" case above) or advertised with a different origin (because all the address space covered is being announced with longer prefixes from another AS). Since today, there are also some pretty(?) pictures showing prefix length distribution from my view of the BGP table. Regards, James
Current thread:
- Re: /24's run amuck?, (continued)
- Re: /24's run amuck? Randy Bush (Feb 24)
- Re: /24's run amuck? Kevin Oberman (Feb 24)
- Re: /24's run amuck? Christian Nielsen (Feb 24)
- Re: /24's run amuck? Christian Nielsen (Feb 24)
- Re: /24's run amuck? Richard A. Steenbergen (Feb 24)
- Message not available
- Re: [NANOG] /24's run amuck? Hank Nussbacher (Feb 24)
- Re: /24's run amuck? Richard A. Steenbergen (Feb 24)
- Re: /24's run amuck? Danny McPherson (Feb 24)
- Re: /24's run amuck? Danny McPherson (Feb 24)
- Re: /24's run amuck? Valdis . Kletnieks (Feb 24)
- Re: /24's run amuck? James Aldridge (Feb 24)
- Re: /24's run amuck? Josh Richards (Feb 24)
- Re: /24's run amuck? Valdis . Kletnieks (Feb 24)
- Re: /24's run amuck? Richard A. Steenbergen (Feb 24)
- Re: /24's run amuck? Richard A. Steenbergen (Feb 24)
- Re: /24's run amuck? Basil Kruglov (Feb 24)
- Re: /24's run amuck? Hank Nussbacher (Feb 24)
- Re: /24's run amuck? William Allen Simpson (Feb 24)
- Re: /24's run amuck? Basil Kruglov (Feb 24)
- Re: /24's run amuck? Randy Bush (Feb 24)