[c-nsp] prefix lists updates and max prefix filters

Gert Doering gert at greenie.muc.de
Thu Dec 8 13:35:34 EST 2011


Hi,

On Thu, Dec 08, 2011 at 09:54:54AM -0800, Mack McBride wrote:
> I should have said not filtering with a prefix list is not really an answer.
> Any time the route-map has to be changed you can and often do get leakage.

There is no need to ever change that route-map.  Which is the great
thing about this scheme :-)

> Therefore you need a second method of filtering.

No...

> The upstream should also be filtering.

Yes.

> <rant> If everyone used route registries to generate prefix lists and kept them up to date 
> this wouldn't be as much of an issue. </rant>
> 
> Thankfully with IPv6 most ASNs will only have one prefix and most of these issues are
> significantly reduced.  Ie. The prefix list at this point has a maximum of 7K entries.

True, but IPv6 won't magically make those lazy upstreams start filtering
their downstreams.  Even if it's less lines of auto-generated prefix lists.

gert
-- 
USENET is *not* the non-clickable part of WWW!
                                                           //www.muc.de/~gert/
Gert Doering - Munich, Germany                             gert at greenie.muc.de
fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de
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