Re: FIB Sizing

[Pablo Lucena <plucena () coopergeneral com>]

> > 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
​There are also features such as Selective RIB Download (or its equivalent
in other vendors) which help out in different portions of the network.​
Definitely not applicable to all router types though.