Route table growth and hardware limits...talk to the filter

Nathan Ward nanog at daork.net
Sat Sep 8 14:46:20 UTC 2007


On 8/09/2007, at 3:45 PM, Leo Bicknell wrote:

> In a message written on Fri, Sep 07, 2007 at 07:14:01PM -0400, Jon  
> Lewis wrote:
>> For some reason, today I started out with fewer routes  
>> (228289...yesterday,
>> I started with 230686) with no filtering.
>>
>> RIR filter section	Reduction in routes
>> APNIC			16690
>> ARIN			41070
>> RIPE			16981
>> LANIC			 4468
>> AFRINIC			 1516
>> -----------------------------
>> TOTAL			80725
>>
>> The end result of applying all the RIR minimum allocation filters was
>> 147564 BGP routes.  I haven't checked to make sure there was no  
>> loss in
>> reachability...this is just an idle 7206/NPE225 with nothing but its
>> ethernet uplink.
>
> The CIDR report states that we have 235647 routes that could be
> aggregated to 154503 routes.  While not the same metric, I'd be
> surprised at 147,564 routes if you did not have reachability issues.

The difference is roughly 3% of the total prefixes. ((154503-147564)/ 
235647*100)

It wouldn't be hard to run some form of netflow, and gauge the amount  
of traffic to those prefixes. If it's as insignificant as the number  
of prefixes, get/use a 0/0 route.

--
Nathan Ward



More information about the NANOG mailing list