Using non-Cisco GBIC on Catalyst 9200
The “service unsupported-transceiver” command is broken on Cisco Catalyst series running IOS version 16.9.X [1].
Worry not, without updating the IOS version we can still prevent the SFP ports from entering an err-disabled state by issuing the no errdisable recovery cause gbic-invalid
command [2]. I’ve tested with FS and Cables and Kits branded Cisco “compatible” transceivers and not encountered any issues.
[1] https://quickview.cloudapps.cisco.com/quickview/bug/CSCvk03296
[2] https://www.reddit.com/r/networking/comments/f01htf/cisco_9200_service_unsupportedtransceiver_error/