nanog mailing list archives
RE: why not AS number based prefixes aggregation
From: Paul Francis <francis () cs cornell edu>
Date: Mon, 8 Sep 2008 15:31:18 -0400
This thread begs an interesting question: what is the right amount of granularity for load balance? Folks here are saying that one-entry-per-AS is too course...an AS wants to influence load on incoming links, and so it needs multiple entries. On the other hand, it is hard to imagine that we need hundreds of entries per AS, or even dozens. So I'm curious...if we could wave a magic wand and control the exact number of entries any AS needs to advertise, what would folks consider to be roughly the right number of entries? Thanks, PF
-----Original Message----- From: Ricardo Oliveira [mailto:rveloso () cs ucla edu] Sent: Monday, September 08, 2008 1:11 PM To: nanog () merit edu Subject: Re: why not AS number based prefixes aggregation Topological aggregation based on ASN is often too course granularity, see this paper: http://www.cs.ucla.edu/~rveloso/papers/giro.pdf specifically Fig4 is a good example, and sec 4C. Cheers, --Ricardo On Sep 8, 2008, at 6:20 AM, yangyang. wang wrote:Hi, everyone: For routing scalability issues, I have a question: whynot deployAS number based routing scheme? BGP is path vectorprotocol and theshortest paths are calculated based on traversed AS numbers. The prefixes in the same AS almost have the same AS_PATHassociated, andaggregating prefixes according to AS will shrink BGP routing table significantly. I don't know what comments the ISPs make onthis kindof routing scheme. -yang
Current thread:
- Re: why not AS number based prefixes aggregation, (continued)
- Re: why not AS number based prefixes aggregation Nathan Ward (Sep 08)
- Re: why not AS number based prefixes aggregation Scott Brim (Sep 08)
- Re: why not AS number based prefixes aggregation Owen DeLong (Sep 08)
- Re: why not AS number based prefixes aggregation yangyang. wang (Sep 08)
- Re: why not AS number based prefixes aggregation Dave Israel (Sep 08)
- Re: why not AS number based prefixes aggregation Benson Schliesser (Sep 08)
- Re: why not AS number based prefixes aggregation William Herrin (Sep 08)
- Re: why not AS number based prefixes aggregation Christopher Morrow (Sep 08)
- Re: why not AS number based prefixes aggregation Jeroen Massar (Sep 08)
- Re: why not AS number based prefixes aggregation Ricardo Oliveira (Sep 08)
- RE: why not AS number based prefixes aggregation Paul Francis (Sep 08)
- Re: why not AS number based prefixes aggregation Jean-François Mezei (Sep 08)
- RE: why not AS number based prefixes aggregation Paul Francis (Sep 09)
- RE: why not AS number based prefixes aggregation Paul Francis (Sep 08)
- RE: why not AS number based prefixes aggregation Boyd, Benjamin R (Sep 08)