nanog mailing list archives
Re: Route table growth and hardware limits...talk to the filter
From: "Andrew - Supernews" <andrew () supernews net>
Date: Sat, 08 Sep 2007 23:30:03 +0100
"Forrest" == Forrest <forrest () almighty c64 org> writes:
Forrest> Sure, this would fail if a network decided to only announce Forrest> /24's for example without a larger aggregate, but how many Forrest> networks are really doing that? More than you probably imagine. Consider the following table: asn | count | c24 | c23 ----------+-------+------+----- 9583 | 1100 | 1014 | 42 7018 | 1140 | 764 | 125 17488 | 560 | 557 | 0 19916 | 568 | 532 | 6 701 | 729 | 501 | 38 1221 | 474 | 380 | 14 1239 | 572 | 359 | 24 577 | 417 | 337 | 19 209 | 587 | 329 | 38 17557 | 291 | 270 | 1 10292 | 270 | 267 | 2 4802 | 345 | 259 | 25 6140 | 315 | 243 | 16 4323 | 483 | 242 | 12 7474 | 284 | 228 | 8 2386 | 295 | 218 | 9 3301 | 307 | 217 | 30 702 | 392 | 206 | 34 6746 | 279 | 200 | 41 In this, "count" is the number of prefixes originated by the AS that are not covered by any longer prefix (without regard to origin); "c24" is the number of those prefixes which are /24s; "c23" is the number which are /23s. I've cut this table off at 200 - the total number of uncovered /24 routes across all ASes is 51811. Some of the above numbers would be worse if not for the presence of over-large route announcements from other providers (for example, Chinanet announce 125.96.0.0/14 even though 125.99.0.0/16 belongs to hathway.net in India (AS 17488); approximately 230 _more_ /24 routes announced by Hathway are in this range). -- Andrew, Supernews http://www.supernews.com
Current thread:
- Re: Route table growth and hardware limits...talk to the filter, (continued)
- Re: Route table growth and hardware limits...talk to the filter Adrian Chadd (Sep 08)
- Re: Route table growth and hardware limits...talk to the filter Joe Provo (Sep 08)
- Re: Route table growth and hardware limits...talk to the filter Stephen Sprunk (Sep 10)
- Re: Route table growth and hardware limits...talk to the filter bmanning (Sep 11)
- Re: Route table growth and hardware limits...talk to the filter Nathan Ward (Sep 08)
- Forward for filtering, was: Re: Route table growth and hardware limits...talk to the filter Iljitsch van Beijnum (Sep 23)
- Re: Route table growth and hardware limits...talk to the filter Bradley Urberg Carlson (Sep 08)
- Re: Route table growth and hardware limits...talk to the filter Forrest (Sep 08)
- Re: Route table growth and hardware limits...talk to the filter Russ White (Sep 08)
- Re: Route table growth and hardware limits...talk to the filter Forrest (Sep 08)
- Re: Route table growth and hardware limits...talk to the filter Andrew - Supernews (Sep 08)
- Re: Route table growth and hardware limits...talk to the filter Forrest (Sep 08)
- Re: Route table growth and hardware limits...talk to the filter Joe Provo (Sep 09)
- Re: Route table growth and hardware limits...talk to the filter Forrest (Sep 09)
- Re: Route table growth and hardware limits...talk to the filter Stephen Sprunk (Sep 10)
- Re: Route table growth and hardware limits...talk to the filter Kevin Loch (Sep 10)
- Re: Route table growth and hardware limits...talk to the filter Stephen Sprunk (Sep 10)
- Re: Route table growth and hardware limits...talk to the filter Kevin Blackham (Sep 10)
- Re: Route table growth and hardware limits...talk to the filter Jon Lewis (Sep 11)
- Re: Route table growth and hardware limits...talk to the filter Adrian Chadd (Sep 11)
- Re: Route table growth and hardware limits...talk to the filter Russ White (Sep 08)
- Re: Route table growth and hardware limits...talk to the filter Andrew - Supernews (Sep 08)