The value of tmnxStdDestAddrType specifies the type of
host address to be used for the remote SNMP notification
collector. This object indicates the type of address stored
in the corresponding tmnxStdDestAddr object.
If the value of this object is 'unknown', then no messages
will be sent nor will any counters be incremented.
If tmnxStdDestAddrType is not set in the same PDU with
tmnxStdDestAddr, the set request will fail with an
inconsistentValue error.