On 2014-04-16 17:55 , Fredy Kuenzler wrote: > Am 16.04.2014 13:08, schrieb Jeroen Massar: >> More specifics are evil and give weird routing in various locations. > > Not always. When Init7 started to propagate more specifics to it's four > /19 and /18, about 2gig of inbound traffic switched from transit links > to peering links. This is real money and IMHO a valid reason to > propagate selectivly more specific prefixes (i.E. two /20 for one /19).
While you are absolutely right that it is good for traffic engineering (how the heck could I disagree with that? :) When some other entity (especially a transit for other networks) filters those prefixes out, the results will vary. The evil part is in the hidden problem it creates; not even the routing pollution (See also previous response...) > Massiv deaggregation however is indeed evil, and there are just too many > networks out there which do it unconsciously in a very stupid way. > > Init7 is filtering away more than 10000 more specific prefixes from > transit. To explain this a bit further I'd like to point to a > presentation I gave a while ago during NANOG 54. > > https://www.nanog.org/meetings/nanog54/presentations/Monday/Kuenzler.pdf I always liked: http://www.swinog.ch/meetings/swinog7/BGP_filtering-swinog.ppt Always good to see what dogfood gets eaten... :) Greets, Jeroen _______________________________________________ swinog mailing list swinog@lists.swinog.ch http://lists.swinog.ch/cgi-bin/mailman/listinfo/swinog
