Clients associate with a strong signal and then see corrupted transfers. The access-point switch port shows input errors and CRC errors climbing. The radios' retry counters are quiet. Where is the fault?
Select an answer to reveal the explanation.
Short Explanation
The radios are quiet and the switch port is counting damaged frames. Your fault is the Ethernet link, not the channel. A certificate does not increment a CRC counter.
Full Explanation
CRC and input errors on the access-point switch port mean frames are arriving damaged on the wire. The radios' retry counters are quiet and the signal is strong, so the corruption is not on the channel. A Wi-Fi retry would show on the radio. A certificate problem fails authentication, and these clients have already associated. DNS does not climb a CRC counter when a name fails. The access-point port shows input errors and CRC errors climbing. The radios are fine. Client traffic is corrupted on the wire. Check one live client after the change and leave the rest of the floor alone until that client matches the result you expected. Confirm the symptom on the next attempt before changing anything else. Confirm the symptom on the next attempt before changing anything else. Exam caveat: a bad cable, a bad port, or a duplex mismatch can all increment CRC. The counter tells you the wire is the layer. Swapping the cable is the usual next test. Operational check: move the access point to a known-good port and cable, confirm the CRC counter stops, and retest a transfer.