L2 netflow without L3 interface on 6509 VSS?

avanzaadmin · ‎06-09-2010

Hi

I'm just checking if this works though I suspect the answer will be no.

Story is that I recently moved all my L3 interfaces from my two VSS switches to a dedicated core switch. Core switch is reporting both L2 and L3 netflow just fine but I'd much like to keep the option to monitor L2 traffic on the VSS using netflow.

Regards

Fredrik

Giuseppe Larosa · ‎06-09-2010

Hello Fredrik,

until the device has an IP address to be used as source for netflow export packets you should be fine.

However, if netflow accounting for L2 bridged traffic requires the configuration of the L3 interface you are in trouble

but :

>> To enable NetFlow for bridged IP traffic on a VLAN, you must create a corresponding VLAN interface and enter the no shutdown command. The no shutdown command can be followed, if necessary, by the shutdown command.

see

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/netflow.html#wp1157805

So you may be able it, the risk may be that if the VSS should reload you may need to repeat the no shut/shut procedure on the SVI

Hope to help

Giuseppe

avanzaadmin · ‎06-09-2010

Much as I suspected. A layer3 interface is not an option right now.

Thanks

Fredrik