The tmnxPortReasonDownFlags indicates why a port may be in the operationally 'down' state. The following reasons are detected through this object: unknown(0) - Unspecified (or unknown) linklossFwd(1) - A sap using this port has an LLF operational status set to 'fault' lagMemberPortStandby(2) - A lag using this port as a member port has set the member port to 'standby' while configured to keep standby member ports down. ethCfmFault(3) - A facility MEP bound to this port has its dot1agCfmMepHighestPrDefect set to a value other than 'none (0)'. opticalTuning(4) - The DWDM optical receive signal is undergoing tuning and analysis by control algorithms to find the optimal settings. channelOutOfRange(5) - The configured DWDM optical channel is out of range for the equipped tunable optical interface. channelNotConfigured(6) - The DWDM optical channel is not configured for the equipped tunable optical interface. crcError(7) - CRC errors on the port exceeded the configured threshold. internalMacTxError(8) - An internal MAC tx error was detected on the port. efmOamDown(9) - dot3OamOperStatus is not 'operational'. symMonError(10) - Symbol Monitor Errors on the port exceeded the configured threshold. satHostPortDown(12) - The host port for this satellite uplink port is down. satUplinkPortDown(13) - The active satellite uplink port for this satellite client port is down.