This action component, when specified, will cause the potential list of egress interfaces for a given packet to be limited to those interfaces that are included in the egress interface mask specified by this attribute. A packet will only be transmitted out interfaces that are both identified through this attribute AND through the normal forwarding logic. Potential egress interfaces are identified by setting the bit in the egress mask that corresponds to the ifIndex value associated with the interface. Each bit of this bit mask corresponds to an ifIndex value, with the most significant bit of the i-th octet of this octet string corresponding to the ((8*i) - 7)-th ifIndex, and the least significant bit of the i-th octet corresponding to the (8*i)-th ifIndex. A zero length octet string indicates that this action component has not been set to an appropriate value and should not be used for action initiation. Egress interface restrictions will not be updated based on QoS classification in this case.