[AusNOG] Cisco 6500 with Sup 720 3BXL - Good routing platform ??

[Bill Walker]

On Mon, 20 Sep 2010 10:06:00 +1000, Lincoln Dale <ltd at cisco.com> wrote:
> On 20/09/2010, at 8:33 AM, Bill Walker wrote:
> 
>> With three upstream providers, you may have issues with the maximum
>> number of routes. The 720 3BXL only supports 1 million routes, sounds
>> like alot but if you have three full international tables, the table
>> isn't big enough as each one will be around 336,000 prefixes.
> 
> this is not correct.  the hardware supported 1M FIB prefixes.  routes !=
> prefixes.
> only the 'best' route is populated from the routing table (RIB) into the
> forwarding table (FIB).
> 
> note also that the FIB can have multiple destinations for equal-cost
> prefixes and that still does not consume more than 1 FIB entry.
> 

Excellent, thanks for the correction, I must have missed/mis-understood
that when reading through the architecture docs. 

Cheers,

Bill