nanog mailing list archives
Re: /24's run amuck?
From: Valdis.Kletnieks () vt edu
Date: Wed, 07 Feb 2001 00:03:02 -0500
On Tue, 06 Feb 2001 15:07:10 MST, Danny McPherson <danny () ambernetworks com> said:
Umm... because if you filter the /24s you will remove 58K of 95K, or some 61%. I'm *sure* that having a routing table 40% of the original size will help the next time you have a BGP flap.Of course, some attentive customers MAY notice reachability issues with those 58K prefixes, but no big deal, at least the routing table is smaller. Heck, might as well go ahead and filter /23 and longer, that'll loss another ~10K, or better yet... :-)
Hey, I *said* your milage may vary. ;) 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% ;) Valdis Kletnieks Operating Systems Analyst Virginia Tech
Current thread:
- Re: /24's run amuck?, (continued)
- Re: /24's run amuck? Vijay Gill (Feb 24)
- 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)