[afnog] Re: The Cidr Report

Geoff Huston cidr-report at potaroo.net
Sun Nov 14 11:23:28 EAT 2004


> > e.g. is AS18566 the origin AS for 751 prefixes that could be
> > collapsed to 6?
> >
>
>         Sort of - from here it looks like they aren't actually announcing
>the supernets.


The covering /162, /15 and /14 aggregates are being globally announced, and 
the more specifics are being announced from the same origin AS, apparently 
along the same AS paths as the specifics, so its not clear that there is 
any form of traffic engineering or load balancing going on.

regards,

    Geoff


> >   o and who can hack the perl to generate filters for this
> >     so we can listen only to the aggregates
> >
>
>         I don't see their stuff listed in the radb, so it looks like you
>have to go to the router itself to read the routes to determine what they
>are announcing, then ask the appropriate registry which block they
>are announcing from, aggregate the routes in that block, rinse and repeat,
>aggregate the aggregated blocks, then filter.
>         ..but that only works if they announce the supernets. Without that
>I'm not sure what you can do that wouldn't end up biting you back. It's also
>a lot of work for not too much reward as long as these messes are the
>exception and not the rule.
>
>         Plus the public hand slap is kind of amusing. But that's probably
>just me.
>
>         Austin




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