Which technique allows an attacker logged into a computer attached to switch port 8 to see traffic sent to hosts on other ports?

A switch maintains a Content Addressable Memory (CAM) table mapping MAC addresses to ports. When an attacker floods the switch with thousands of spoofed MAC addresses, the CAM table overflows and the switch can no longer make forwarding decisions, so it broadcasts all frames out every port - effectively behaving like a hub. This allows the attacker on port 8 to capture traffic intended for all other ports.

Releasing and renewing a DHCP lease only changes the host's IP address and has no effect on how the switch forwards Ethernet frames to other ports.

Switches do not maintain DNS caches - DNS cache poisoning targets resolvers and clients to redirect name resolution, not switch forwarding behavior.

Promiscuous mode configures the NIC to accept all frames it receives, but without flooding the CAM table the switch still delivers only relevant frames to port 8, so there is nothing extra to capture.