[c-nsp] Layer 2 vs Layer 3 Performance Question

[Kevin Graham]

> The only thing I can see as a difference is if I trunk the iSCSI vlan, 

> then the traffic never hits the 6509's routing module. Maybe that helps 
> performance?

No. Assuming the 6500 isn't a relic with an MSM or Sup1/Sup1A, there
should be no difference in L2 and L3 forwarding performance (PFC does
both) -- if you're seeing anything but trivial CPU utilization on the
MSFC (presuming from your description that there isn't any heavy BGP
involved), then something is misconfigured.

The routed approach you have now is preferable -- namely, no unknown
unicast flooding between buildings and obvious traffic patterns between
the two.