First do you need to setup port mirroring on a switch in order to capture everything on the network or just a NIC running in promiscuous mode?
Tried to setup port mirroring on a Netgear switch: (Spare switch)
Connected the corporate network to the source port (flat network setup, no VLANs)
Connected the sniffing PC to the designation port
Could not connect to the corporate network.
Tried to configure a static but still could not communicate through the source/destination ports. However if the PC was plugged into any other port then I could access the network.