North American Network Operators Group
Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

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

  • From: Nathan Ward
  • Date: Sat Sep 08 11:02:41 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