Indicate the mask to be logical-ANDed with the destination address
before being compared to the value in the usdIpRouteStaticDest field.
For those systems that do not support arbitrary subnet masks, an agent
constructs the value of the usdIpRouteStaticMask by reference to the IP
Address Class.
Any assignment (implicit or otherwise) of an instance of this object to
a value x must be rejected if the bitwise logical-AND of x with the
value of the corresponding instance of the usdIpRouteStaticDest object is
not equal to usdIpRouteStaticDest.