Using 3rd Party SFP modules in Cisco Devices

All SFP modules contain in their EEPROM, a Serial Number, Vendor Name & ID, Security code and a CRC. The Switch checks this information, if it can't verify it might give messages like the following:

%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

There are two undocumented cisco commands to get 3rd party SFP modules to work:

switch(config)# service unsupported-transceiver
switch(config)# no errdisable detect cause gbic-invalid