[44223] in North American Network Operators' Group
Re: BGP Route Damping
daemon@ATHENA.MIT.EDU (Pete Templin)
Tue Nov 13 13:10:10 2001
Date: Tue, 13 Nov 2001 12:09:04 -0600 (EST)
From: Pete Templin <templin@urdirect.net>
Reply-To: Pete Templin <templin@urdirect.net>
To: German Martinez <gmartine@nic.gip.net>
Cc: nanog@merit.edu
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On Tue, 13 Nov 2001, German Martinez wrote:
> Perhaps this document was already discussed (I'm new in this list). If it
> was please let me know. Basically, I wanted to get an opinion from US
> based ISP about this document.
>
> Does somebody know how Tier-1 networks implement route damping ?
>
> Here is the document:
>
> http://www.ripe.net/docs/ripe-210.html
I can't speak for any large networks, but I will say that you need to
adjust a portion of that configuration to actually achieve dampening of
/24s and longer. In:
route-map graded-flap-damping permit 20
match ip address prefix-list min24
set damp 30 750 3000 60
you will need to change the numbers in the final line, as there is a
fundamental equation that needs to be followed:
2x(max-suppress/half-life) must be greater than (suppress/reuse).
So you'll need to increase either the max-suppress (60) or the reuse
(60), or decrease the half-life (30) or the suppress (750).
Pete
--
Peter J. Templin, Jr., CCNP, CCDP
Networking Consultant
On-Line Internet Services - URDirect.net
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