Today saw me in a spot where I had a dead Fiber SFP. You guessed it. 3750 chassis. Well I only had a few laying around and some were Linksys and one was stripped of stickers.
Needing this link back up whilst I waited for a new one I plugged in a non-Cisco SFP. Behold the error.
123 %PHY-4-UNSUPPORTED_TRANSCEIVER: Unsupported transceiver found in Gi1/0/1%GBIC_SECURITY_CRYPT-4-VN_DATA_CRC_ERROR: GBIC in port 65538 has bad crc
All SFP/GBIC’s contained burnt in Hardware ID, Vendor Name, Serial and CRC. The following command which is undocumented allows to bypass this error and brings up the interface!
12 LAB-SW-A(config)# service unsupported-transceiverLAB-SW-A(config)# no errdisable detect cause gbic-invalid
Voila! There you go. Quick fix. Just note that when you issue a Show Tech for TAC, it will reveal that you have suppressed this message and that you have overridden support of Cisco Only SFP/GBICs. That means no help!