Current state of the port. There are five possible states:
- Link down (cable not plugged in)
- Blocked (link OK but no network traffic except for RSTP frames is passed, inactive port)
- Listening (port is active in topology)
- Learning (port active and learning MAC addresses, still no passing traffic)
- Forwarding (port active and passing network traffic)
Ethernet frames with user data can be sent or received by a port only if it is in Forwarding state.
In all other states, only sending and receiving of RSTP frames is possible on that port.
- Link down (cable not plugged in)
- Blocked (link OK but no network traffic except for RSTP frames is passed, inactive port)
- Listening (port is active in topology)
- Learning (port active and learning MAC addresses, still no passing traffic)
- Forwarding (port active and passing network traffic)
Ethernet frames with user data can be sent or received by a port only if it is in Forwarding state.
In all other states, only sending and receiving of RSTP frames is possible on that port.