Which port state indicates that a port is actively forwarding frames?

The port state that indicates a port is actively forwarding frames is Forwarding. In this state, the port is fully operational, meaning it can send and receive data packets. When a port is in Forwarding mode, it actively participates in the network by allowing traffic through, making it essential for efficient communication within a switched network.

In contrast, the Blocking state prevents the port from sending or receiving any data frames, thereby avoiding possible loop conditions in a network. The Learning state allows the switch to learn the MAC addresses of devices connected to that port, but it does not forward frames yet. The Listening state enables the switch to listen for BPDUs (Bridge Protocol Data Units) to determine the overall topology of the network, but like the Learning state, it does not forward frames. Thus, Forwarding is the state where active data transmission occurs, ensuring the smooth flow of network traffic.