I have a wired ethernet connection. My PC is connected to a CISCO Switch This switch is NOT in mirrored mode.
When I startup Wireshark (with promiscuous mode on). I see every bit of traffic on the network (not just broadcasts and stuff to .255.)
When I turn promiscuous off, I only see traffic to and from my PC and broadcasts and stuff to .255.
The wireshark application is running on my computer that is wired. It doesn't get packets unless it traverses that physical wire. The switch shouldn't be seeing the traffic whether I have promiscuous on or not. I've tried the same on a wired laptop (different VLAN) and it behaves the same.
This is a switch, not a hub. Could wireshark somehow be telling the switch to send all packets?