[c-nsp] Prefix-list help

[Gert Doering]

Hi,

On Tue, Oct 16, 2007 at 07:53:26AM -0400, Chris O'Hair wrote:
> I have a prefix-list for incoming updates to filter out bogons but its
> not checking for minimum lengths.  Can someone help me out with a
> prefix-list statement that will block this nastiness but not remove
> any useful aggregation?

ip prefix-list no-ultra-short-things deny 0.0.0.0/0 le 7

should do that - remove all from /0 (default route) to /7.  Permit /8 and up.

OTOH, unless you are running into CEF updating problems, why bother?  If 
you have a more specific route, it will win - and if not, the /1 will do
the same thing as getting a default route from your upstream "catch-all".

gert

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Gert Doering - Munich, Germany                             gert at greenie.muc.de
fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de