802.1D Port States

Posted: 29th March 2021 by ccna7guru in SRWE
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802.1D Port States
In the 802.1D STP protocol, every port transitions through the following states:
Disabled: The port is in an administratively off position (that is, shut down).
Blocking: The switch port is enabled, but the port is not forwarding any traffic to
ensure that a loop is not created. The switch does not modify the MAC address table.
It can only receive BPDUs from other switches.
Listening: The switch port has transitioned from a blocking state and can now send or
receive BPDUs. It cannot forward any other network traffic. The duration of the state
correlates to the STP forwarding time. The next port state is learning.
Learning: The switch port can now modify the MAC address table with any network
traffic that it receives. The switch still does not forward any other network traffic
besides BPDUs. The duration of the state correlates to the STP forwarding time.
The next port state is forwarding.
Forwarding: The switch port can forward all network traffic and can update the
MAC address table as expected. This is the final state for a switch port to forward
network traffic.
Broken: The switch has detected a configuration or an operational problem on a port
that can have major effects. The port discards packets as long as the problem continues
to exist.