This read-only CoriantTypesEthFec value reports the FEC working state actually in effect on this 10 Gigabit Ethernet (10GbE) client port, defaulting to disabled, as distinct from the configured FEC type. This tells an operator whether FEC is genuinely active on the link right now, which matters because a configured FEC type does not always mean it successfully negotiated or engaged with the far end. For example, if the configured eth type shows a specific FEC mode but this state object still reads disabled on client port 3, that mismatch would indicate FEC negotiation with the attached client device did not succeed.