Port States and Roles Flashcards
7 cards from real STP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Port States and Roles flashcards as text
Which combination of port state and role correctly describes a port that is actively forwarding data on the root bridge?
Answer: Forwarding / Designated Port
All ports on the root bridge are Designated Ports and, when active, they are in the Forwarding state.
PortFast should only be enabled on which type of ports to avoid STP loops?
Answer: Ports connected to end-user devices (access ports)
PortFast bypasses the Listening and Learning states, so it must only be used on access ports connected to end devices that cannot generate BPDUs.
When a switch port enabled with RSTP is connected to an end device and transitions immediately to Forwarding, what RSTP port role and type does it use?
Answer: Designated Port / Edge
RSTP Edge Ports act like PortFast and go directly to Forwarding; they are Designated Ports serving end-device segments.
A non-root switch has two paths to the root bridge with equal cost. The first path uses a port with priority 128 and port number 1; the second uses priority 128 and port number 2. Which port becomes the Root Port?
Answer: Port 1, because lower port ID wins
When path cost and port priority are equal, STP selects the port with the lower port number, making Port 1 the Root Port.
Which STP port state immediately precedes the Forwarding state during normal port initialization?
Answer: Learning
A port transitions from Listening → Learning → Forwarding; the Learning state is the final intermediate state before a port begins forwarding data.
In IEEE 802.1D, a non-designated port that is in the Blocking state is sometimes called what?
Answer: Non-Designated Port
In 802.1D terminology, ports that are not the Root Port or a Designated Port are called Non-Designated Ports and are placed in the Blocking state.
If a switch receives a superior BPDU on its current Root Port, what happens to that port's role?
Answer: It may become a Blocked or Alternate Port as STP reconverges
Receiving a superior BPDU triggers STP reconvergence; the current Root Port may lose its role and be blocked if another path to the root becomes preferred.