This attribute indicates the bit mask indicating the significant bits
which are used in the comparison of an incoming IP address against
the 'friendly' IP address in the instance value of the IpAccess
component. This bit mask is ANDed to the incoming IP address,
and ANDed to the instance value, before the comparison.
An IP subnetwork address, in combination with this bit mask
attribute, may be provisioned to include an entire IP subnetwork
into the friendly IP address list with a single IpAccess component.