The value of tmnxOspfNgIfMD5TransmitKeyId indicates the index value
used to access the row entry in the tmnxOspfNgIfMD5KeyTable that
specifies the authentication type and key transmitted on this
OSPF interface. This object is valid only when tmnxOspfVersion
has the value 'version2'.
If tmnxOspfNgIfMD5TransmitKeyId has a value of 0, it means that no
keys are configured.