The value of tmnxOspfIfMD5TransmitKeyId indicates the index value
used to access the row entry in the tmnxOspfIfMD5KeyTable that
specifies the authentication type and key transmitted on this
OSPF interface. This object is valid only when tmnxOspfVersion
has the value 'version2'.
If tmnxOspfIfMD5TransmitKeyId has a value of 0, it means that no
keys are configured.