OT: Monitoring 3550 routed traffic w SNMP

Hi all,
just learned that aparently the 3550s do not show
cef switched (routed) packets in reports for VLAN interfaces.

So if you do a show int vlan x, you do not see traffic,
other than that which is punted to the processor,
and SNMP counters follow the same info.

Disabling cef would do, but obviously that is out of the
question.

My goal is to be able to monitor the vlan traffic. Any idea ?
I'm leaning to set up a monitor session to copy vlan traffic to
a port and have its counters used as vlan monitor :)

But cleaner ideas are welcome.

Thanks,

-- 
Carlos G Mendioroz  <tron_at_huapi.ba.ar>  LW7 EQI  Argentina
Blogs and organic groups at http://www.ccie.net