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300-420 · Question #156

Refer to the exhibit. An architect reviews the low-level design of a company's enterprise network and advises optimizing the STP convergence time. Which functionality must be to Gi1/0/1-10 to follow…

The correct answer is A. PortFast. PortFast should be applied to Gi1/0/1-10 to optimize STP convergence time on access-layer ports connected to end devices (PCs, servers, printers). Without PortFast, an STP port transitions through Blocking → Listening (15s) → Learning (15s) → Forwarding, causing a 30-second…

Advanced Enterprise Campus Networks

Question

Refer to the exhibit. An architect reviews the low-level design of a company's enterprise network and advises optimizing the STP convergence time. Which functionality must be to Gi1/0/1-10 to follow the architect's recommendation?

Exhibit

300-420 question #156 exhibit

Options

  • APortFast
  • Broot guard
  • CUplinkFast
  • DBPDU guard

How the community answered

(34 responses)
  • A
    88% (30)
  • B
    3% (1)
  • C
    3% (1)
  • D
    6% (2)

Explanation

PortFast should be applied to Gi1/0/1-10 to optimize STP convergence time on access-layer ports connected to end devices (PCs, servers, printers). Without PortFast, an STP port transitions through Blocking → Listening (15s) → Learning (15s) → Forwarding, causing a 30-second delay before the port becomes usable. PortFast bypasses the listening and learning states, bringing the port immediately to forwarding state, which dramatically reduces convergence time for end-host connections. Root Guard (B) prevents unauthorized switches from becoming the root bridge and is applied on designated ports facing potential rogue switches-not end-device ports. UplinkFast (C) accelerates convergence on uplink ports toward the distribution layer when a primary uplink fails. BPDU Guard (D) is a complementary security feature often paired with PortFast that shuts down a PortFast-enabled port if it receives a BPDU, but BPDU Guard alone does not speed up convergence.

Topics

#STP#PortFast#Convergence Optimization#Access Layer

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