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Re: BGP Filtering

  • From: Christopher Morrow
  • Date: Tue Jan 15 22:15:14 2008
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On Jan 15, 2008 2:02 PM, Jon Lewis <jlewis@xxxxxxxxx> wrote:
>
> On Tue, 15 Jan 2008, Ben Butler wrote:
>
> > I want a filter that will automatically match the shorter prefixes that
> > match any longer prefix, once I can match them I can drop them.
> > I don't want to manually configure a static prefix list for lots and
> > lots and lots of reasons.
> > If the longer prefix disappears from the route table I want to stop
> > filtering the shorter prefixes - automatically.
>
> This was talked about / requested several months ago on cisco-nsp.  IIRC,
> the thread ended along the lines of don't hold your breath.
> Implementation of this sort of feature is very icky (lots of details you
> may not be considering) and why should cisco spend time writing this code
> when they can sell you a bigger router instead?
>

Jon, didn't you start:

http://www.wibble.co.uk/archives/nanog/2007/msg05265.html

and Ben, is this sort of what you are looking for? Or would it
accomplish the same thing for you?

-Chris