[c-nsp] flow-export to more than 2?

[Simon Leinen]

Nick Hilliard writes:
> On 27 Feb 2011, at 11:49, Simon Leinen <simon.leinen at switch.ch> wrote:
>> Not much of a risk because Hank has 7600s, which don't know how to send
>> Netflow packets over IPv6 (although thankfully they can produce Netflow
>> accounting from IPv6 traffic now).

> For l3 traffic only. Still can't export l2 ipv6 netflow data, even
> though the records can be viewed on the PFC. :-(

I hadn't known about that particular restrictions, but there are others:

* The AS number fields "aren't filled in" in IPv6 flows.  I understand
  that this is because the thing that paints the Netflow records doesn't
  have access to the IPv6 BGP table.

* The prefix-length fields "aren't filled in" either.  Less clear to me
  whether the previous explanation applies here.

"Aren't filled in" is the blatant euphemism that Cisco loves to use when
they export fields as ZERO because they don't know how to get the data.
FOLKS: If you cannot compute a field, DON'T EXPORT IT.  Netflow v9 has
templates, dammit! So simply use a template without those fields.
-- 
Simon.