nanog mailing list archives

Re: FIB Sizing


From: William Herrin <bill () herrin us>
Date: Sat, 25 Jul 2015 15:27:08 -0400

On Sat, Jul 25, 2015 at 7:28 AM, Baldur Norddahl
<baldur.norddahl () gmail com> wrote:
When will router vendors learn to do even simple aggregation before loading
routes into FIB? It appears that most hardware will have plenty of FIB
space if this was done. Also that aggregated routes are increasing at a
slower pace.

Howdy,

You can get a good reduction with FIB aggregation, but only upwards of
50% or so, and that only with the some pretty costly algorithms. Also,
you tend to get better gains at the cheaper edge nodes rather than the
more expensive core nodes. For now it's more cost effective to leave
the code alone and just double the size of the TCAM.

Regards,
Bill Herrin


-- 
William Herrin ................ herrin () dirtside com  bill () herrin us
Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>


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