Examkin

Question

Difficulty: EasySpanning Tree Protocol Operations

During the operation of IEEE 802.1D Spanning Tree Protocol (STP), a switch port transitions through multiple operational states. Which of the following activities occur specifically while a port is in the Learning state? (Select TWO.)

  1. It populates the switch MAC address table using source MAC addresses from incoming data frames.Answer
  2. It transmits and processes Bridge Protocol Data Units (BPDUs) received from neighboring switches.Answer
  3. C
    It forwards user payload data frames between connected network interfaces.
  4. D
    It discards all BPDUs to prevent premature topology calculations.
  5. E
    It reconfigures the interface 802.1Q trunk native VLAN assignment.

Answer

In the IEEE 802.1D Learning state, the switch port processes BPDUs and populates its MAC address table, but it does not yet forward user data frames.
During the standard IEEE 802.1D Learning state, a switch port actively processes and sends BPDUs while learning source MAC addresses from received frames to populate the MAC address table. However, to prevent switching loops during convergence, it does not forward user payload frames.

Step-by-Step Solution

1
Identify the primary functions of the 802.1D Learning port state.
The Learning state is designed to prepare the switch for forwarding traffic by learning MAC addresses without actually forwarding frames.
Populating the MAC table prior to forwarding prevents excessive unicast flooding upon entering the Forwarding state.
2
Evaluate control plane vs. data plane behavior during the Learning state.
Control plane BPDUs are sent and received, MAC table entries are updated from incoming frames, but user data traffic is not forwarded.
Restricting data frame forwarding during convergence prevents temporary switching loops while topology details stabilize.

Key Concept

802.1D Spanning Tree Protocol Port State Operations
Rate this question

Topics

Spanning Tree Protocol Operations

More questions from this topic