nanog mailing list archives
RE: BellSouth prefix deaggregation (was: as6198 aggregation event)
From: "McBurnett, Jim" <jmcburnett () msmgmt com>
Date: Sun, 12 Oct 2003 15:07:46 -0400
IMHO, I think we should create a route-set obj like call it... RS-DEAGGREGATES and list all the major irresponsible providers's specific /24's in it...
CASE: Business has a /24 from X provider in order to multihome. That /24 is de-aggregated from a /19, with this policy that /24 may not be routed. possible exception: When 2002-3 get passed by ARIN, this could even take on new meaning. ARIN says they will use a single /8 for the handing out of /22-/24 for multihoming end users. will you then filter those /24's also? Also: What happens when that /24 for Business Y noted above is dual routed by ISP A and ISP B, and ISP A's upstream filters but ISP B's does not? Will there be asymmetric routing? Finally: Can anyone from BellSouth, explain the end goal of the de-aggregation? I suspect with 40 + ASs they may be rebuilding their network with a recently announced list of new IP services and DSL growth as asked for under the Federal government Rural DSL regulations... (I'm not trying to defend them, just giving some possibilities)
So some ASes who wish to not accept deaggregated specifics using RPSL can update their AS import policy to not import RS-DEAGGREGATES...
Just my humble opinion.. Comments/critics welcome :) -hc -- Haesu C. TowardEX Technologies, Inc. Consulting, colocation, web hosting, network design and implementation http://www.towardex.com | haesu () towardex com Cell: (978)394-2867 | Office: (978)263-3399 Ext. 170 Fax: (978)263-0033 | POC: HAESU-ARIN On Sun, Oct 12, 2003 at 11:26:49AM -0400, Jared Mauch wrote:On Sun, Oct 12, 2003 at 01:02:57PM +0000, Stephen J. Wilcox wrote:Can anyone from BellSouth comment? What if a few othermajor ISPs wereto add a thousand or so deaggregated routes in a fewweeks time? Wouldthere be a greater impact?one word - irresponsibleThis clearly stands out to me as a reason to keep and use prefix filtering on peers to reduce the amount of junk inthe routingtables. If bellsouth needs to leak more specifics for loadbalancingpurposes, fine, just make sure those routes don't leaveyour upstreamsnetworks and waste router memory for the rest of us thatdon't need tosee it. - Jared(Note: The above numbers are based on data fromcidr-report.org. Someother looking glasses were also checked to see ifcidr-report.org's viewof these AS's is consistent with the Internet as awhole. This appearsto be the case, but corrections are welcome.) -Terry-----Original Message----- From: owner-nanog () merit edu [mailto:owner-nanog () merit edu] On Behalf Of Terry Baranski Sent: Sunday, October 05, 2003 3:01 PM To: 'James Cowie'; nanog () merit edu Subject: RE: as6198 aggregation event James Cowie wrote:On Friday, we noted with some interest theappearance of morethan six hundred deaggregated /24s into the global routing tables. More unusually, they're still in therethis morning.AS6198 (BellSouth Miami) seems to have beenpatiently injectingthem over the course of several hours, betweenabout 04:00 GMTand 08:00 GMT on Friday morning (3 Oct 2003).If you look at the 09/19 and 09/26 CIDR Reports,BellSouth Atlanta(AS6197) did something similar during this timeperiod -- they addedabout 350 deaggregated prefixes, most if not all /24's.Usually when we see deaggregations, they hitquickly and theydisappear quickly; nice sharp vertical jumps in thetable size.This event lasted for hours and, more importantly,the prefixeshaven't come back out again, an unusual pattern fora single-originchange that effectively expanded global tables byhalf a percent.That AS6197's additions are still present isn't encouraging. -Terry-- Jared Mauch | pgp key available via finger fromjared () puck nether netclue++; | http://puck.nether.net/~jared/ Mystatements are only mine.
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- RE: BellSouth prefix deaggregation (was: as6198 aggregation event) McBurnett, Jim (Oct 12)