A network administrator enables an access switch interface connected to a workstation running standard IEEE 802.1D Spanning Tree Protocol (STP) without PortFast configured. Arrange the standard operational port states in the exact chronological sequence through which the interface transitions from initial link activation to full user data frame transmission.
- 1The interface enters the Blocking state: it processes incoming BPDUs to determine topology roles, but discards user data frames and does not learn MAC addresses.
- 2The interface transitions to the Listening state: it actively sends and receives BPDUs to determine Root Bridge and Port Role assignments, while continuing to discard data frames and refrain from learning MAC addresses.
- 3The interface transitions to the Learning state: it continues BPDU exchange and begins inspecting source MAC addresses of incoming frames to populate the MAC address table, but does not yet forward data frames.
- 4The interface transitions to the Forwarding state: it actively processes, populates, and forwards user data frames while continuing regular BPDU transmission and reception.
Answer
The correct chronological sequence for standard IEEE 802.1D STP port state initialization is: Blocking state, Listening state, Learning state, and finally Forwarding state.
Under standard IEEE 802.1D Spanning Tree Protocol operational behavior, an interface enabling without PortFast goes through a strict multi-step sequence to prevent Layer 2 loops. It begins in the Blocking state (discarding data, listening to BPDUs), transitions to Listening (exchanging BPDUs, electing roles for 15 seconds), advances to Learning (exchanging BPDUs and building MAC address table for 15 seconds), and culminates in the Forwarding state (full data frame transmission and MAC learning).
Step-by-Step Solution
Key Concept
IEEE 802.1D Spanning Tree Protocol Port State Transitions
Estimated Time:2m 0s