[c-nsp] Cat 6500 and counters

[Andrey Zimin]

> > On Wed, Apr 27, 2005 at 02:41:36PM -0700, Kevin Graham wrote:
> > [..]
> > > > What about netflow?  Does it work on the Sup2/MSFC2 
> and/or the Sup720?
> > > > I saw one post claiming "v5 only", so IPv6 netflow isn't there?
> > > 
> > > Doubt v9 exports are there yet, but your biggest caveat 
> will be that
> > > you'll have to do sampled netflow to avoid killing the 
> Sup cpu. This
> > > is my single biggest gripe w/ the platform.
> > 
> > Can someone else confirm this, that "unsampled netflow" will be a 
> > CPU problem?
> 
> No, netflow does not have any impact on CPU at all - netflow 
> statistics 
> collected at "hardware" level.
> 
> > For billing, we won't need netflow on most of the ports, 
> but for some
> > parts of the network, we can't do without (yet), and 
> sampled netflow is
> > BAD for that (if just because there have been some cases in 
> court recently
> > where the court said "this is not science, this is just 
> guesswork, it
> > cannot be accepted as a serious base for billing").
> 
> Please note that c65 limited on number of active of netflow entries. 
> For sup720-3bxl/sup720-3b this number is relatively high one 
> (~230K entries), 
> but this limit exists... 
In real life you more hit aging limit(30-40 flow/s) and with this:

> PS: one more limitation - you will not be able to limit router to 
> collect netflow data on just some interfaces - it will collect 
> data on all interfaces. 
You can't collect full NF data more than 1-2Gbit/s Internet traffic crossing
Sup720-3bxl box, and more 5Gbit/s with src-dst-if aggregations.
It depends of enviroment, but realy far from expected on router with 10GE interfaces.

So, pay you exclusive attention on NF functions on 6K platform, if u have plan to use it.
It totally different than u can see on other router platforms.

Do the tests in real enviroments, if that possible.

Just my 2c.

WBR,
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Andrey Zimin | AVZ-RIPE
MTU-Intel ISP, Moscow, Russia
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