Switch port LED indications: On a Cisco switch, a port Status LED that alternates between green and amber typically indicates which condition?

Introduction / Context:
Port LEDs on Cisco Catalyst switches provide quick diagnostics without using the CLI. Understanding common color patterns helps network engineers rapidly identify cabling faults, duplex mismatches, or other anomalies.

Given Data / Assumptions:

• We are discussing the Status LED behavior, not Mode LEDs like speed/PoE.
• Alternating green/amber is a distinct pattern from solid green, solid amber, or off.
• Platform families share similar conventions (exact patterns can vary by model).

Concept / Approach:
In general Cisco guidance, steady green means a healthy link, steady amber often indicates STP blocking or a disabled/error state, and alternating green/amber signals a problem such as link faults or excessive errors. Engineers should confirm via documentation for the specific model and verify using CLI counters.

Step-by-Step Solution:

Verification / Alternative check:
If STP blocking were the cause, many models show steady amber (not alternating). Error counters rising in the CLI corroborate the LED indication.

Why Other Options Are Wrong:

• Administrative shutdown typically shows LED off or steady amber, not alternating.
• STP blocking commonly presents steady amber; alternating suggests faults.
• Calling it “normal” or “half-duplex by design” ignores the fault indication.

Common Pitfalls:
Relying solely on LEDs without checking interface logs; misinterpreting model-specific legends—always cross-check the device guide.

Final Answer:
The port is experiencing errors.