[c-nsp] Enabling NetFlow in a C6500 core network

[Peter Rathlev]

Hi Ruben,

On Wed, 2008-06-18 at 12:27 +0200, Ruben Montes (Europe) wrote:
> I need to enable NetFlow support in our customer's core 6500 sup720.
> 
> I'd like to know if enabling the command "mls flow ip interface-full"
> and "ip flow-ingress" in every L3 VLAN can cause any disruption in the
> traffic.

Adding "ip flow ingress" to an interface doesn't interrupt anything, we
recently added this to a part of our network with no problems.

I'm not sure about changing the flowmask, but you can see the currently
used with "show mls netflow flowmask". IIRC default for Sup720 is null.
It just tested it on a SXF5, and a flood ping both to and through the
box (12 ms interval) didn't miss a single packet when issuing "mls flow
ip interface-full".

> Is there any additional internal table that is enabled when you
> configure these commands that needs to be built from scratch? Does it
> have any impact in the CPU?

There might be something about flow masks being used for other purposes,
but I don't remember how to find out. And my search-fu is bad right now,
so I can't even find it on cisco.com. :-(

Regards,
Peter