SPAN port and 3548 stacking

[niglio]

I have 2 switches 3548 in stack and i need to monitor ALL the traffic in the 2 switches (not only the traffic going thrught the 2 devices)

I know that 3548 don't support RSPAN;

I suppose i need to define all the ports on both switches in stack as source SPAN ports. Do I need to define a VLAN for all these ports (in both switches the same ) as switch 3548 support SPAN only on port of the same VLAN?

Do I need TWO SPAN port (one for each switch) or i can use ONE SPAN destination port to monitor ALL the traffic throught and in the 2 switches?

[jsalminen]

You won't be able to capture all the packets from both switches with just one SPAN port. You will have to capture each switch independently with one SPAN port on each switch. Don't set all ports to SPAN because all ports will receive (forward) all packets. Kinda like flooding every packet so to speak.