[c-nsp] full routing table / provider-class chassis

[Peter Rathlev]

On Fri, 2009-06-12 at 12:58 -0700, Jo Rhett wrote:
> Now let's talk about reality: 1/10 inbound/outbound ratios, 5% of  
> received traffic is Internet cruft requiring (wasted) TCAM lookups,  
> etc and such forth than any provider peering router observes, and  
> you're down to a much lower ratio.  Fail to install DFCs and you'll  
> find your 6509s falling over with just a few gigabits of traffic.    
> 30mpps versus 48mpps gives an illusion that DFCs only give you another  
> 50%, but that's not reality on the ground.  Don't try and persuade me  
> otherwise, I've seen this repeatedly in real life environments.

I tend to agree with this (and your points generally btw), especially
when looking carefully at the subject of this thread. I'd still say "it
depends" though. Sometimes a non DFC enabled box would do the job fine.
It's (mostly) not like the box dies doing nothing. :-)

I would even suspect that many C6k/Sup720s are probably using very
little of their capacity. It's targeted at the enterprise, and I've seen
3BXL boxes in 6 node networks with ~ 50 prefixes in OSPF and nothing
else. I would therefore say that _sometimes_ someone from Cisco or a
partner might upsell a little.

The people that are genuinely worried about the performance would also
know what to do about it and where to look for alternatives.

> Now, let's stop talking about non-DFC cards and start talking about  
> equipment which can handle uRPF on every port, full Netflow analysis  
> of up to 8 ports at a time, every port layer 3, every port filtered,  
> colo facility core/peering.

If this is the target then 6500/7600 isn't really the best tool IMHO.

Regards,
Peter