The value of tmnxNat64InDropZeroIpv4Checksum specifies
if UDP datagrams with zero IPv4 checksum are dropped.
If the value of tmnxNat64InDropZeroIpv4Checksum is equal to 'false',
the system calculates the IPv6 checksum for each such datagram.
The value of this object can only be modified while the value of
the object tmnxNat64InAdminState is equal to 'outOfService'.