Use Third Party SFP Modules on Cisco Devices

Usually you will need a Cisco – SFP Module for each Cisco device, but there is an undocumented (and unsupported!) CLI command to be able to use (cheaper) third party modules. Although this is not recommended (and should never be used in a production environment) it is a cheap method to set up a lab environment with your spare Cisco devices.

Normally when connecting a third party SFP you will get an error message on the CLI stating

%PHY-4-UNSUPPORTED_TRANSCEIVER: Unsupported transceiver found in Gi1/0/0 %GBIC_SECURITY_CRYPT-4-VN_DATA_CRC_ERROR: GBIC in port 65538 has bad crc

and the associated port will be deactivated automatically.

The command

forces the device to support third party modules additionally with

you can prevent the shutdown of the port with the “wrong” SFP module.

Both commands should be available in IOS 12.2(25)SE and above.

Be aware that Cisco TAC will not give you support for these setups, so in case of a problem before contacting support you will have to switch the unsupported modules with Cisco modules (more information here).


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