Indicate the mask to be logical-ANDed with the
destination address before being compared to
the value in the mplsVpnVrfRouteDest field.
For those systems that do not support
arbitrary subnet masks, an agent constructs the
value of the mplsVpnVrfRouteMask 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 bit-wise logical-AND of x with
the value of the corresponding instance of the
mplsVpnVrfRouteDest object is not equal to
mplsVpnVrfRouteDest.