What happens if PortFast is enabled on an interface connected to another switch?
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Correct answer: Spanning-tree fails to detect a switching loop increasing the likelihood of broadcast storms..
Why this is the answer
PortFast is designed for end-device ports, not switch-to-switch connections. When enabled on a port, PortFast immediately transitions the port to the forwarding state, bypassing the normal Spanning Tree Protocol (STP) listening and learning states. This is beneficial for end devices as it reduces the time they wait to connect to the network. However, if a PortFast-enabled port is connected to another switch, STP will not be able to detect a switching loop because the port skips the states where BPDUs are exchanged and analyzed. This can lead to a Layer 2 loop, causing broadcast storms and network instability. The other options are incorrect because PortFast does not accelerate root port choice or recalculation, it does not shut down ports receiving BPDUs (that's BPDU Guard), and it is unrelated to VTP.
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