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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Route table growth and hardware limits...talk to the filter
>>>>> "Forrest" == Forrest <[email protected]> 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
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