More like a "how-to" question rather than about security, but let's answer

You go to the interfaces window *

Note: "Even in promiscuous mode you still won’t necessarily see all packets on your LAN segment. See the Wireshark FAQ for more information."

*_{(capture>opt>enable promiscuous mode)}

You go to the interfaces window *

Note: "Even in promiscuous mode you still won’t necessarily see all packets on your LAN segment. See the Wireshark FAQ for more information."

*_{(capture>opt>enable promiscuous mode)}