Patent ID: 8621596

Claim:
A method comprising: in response to receipt of a first packet at a first network node of a network, propagating a packet from the first network node to a second network node of the network, wherein the network comprises a plurality of network nodes, the network nodes comprise the first network node and the second network node, the first packet is received from the second network node via the network, the first packet comprises source security group information, and a destination address, the destination address is an address of a destination of the first packet, the source security group information identifies a source security group, a source of the first packet is a member of the source security group, the packet comprises access control information, the access control information comprises the source security group information, destination security group information, and the destination address, the destination security group information identifies a destination security group, the destination is a member of the destination security group, the propagating is performed in response to access control processing performed on the first packet at the first network node after the first packet has been received by the first network node, and the access control processing comprises determining the destination security group information using the destination address; in response to receipt of the packet at the second network node, making a determination as to whether, at the second network node, the destination group identifier can be associated with the destination address; if the determination indicates that, at the second network node, the destination group identifier can be associated with the destination address, associating the destination group identifier with the destination address; and if the determination indicates that, at the second network node, the destination group identifier cannot be associated with the destination address, associating a reserved group identifier with the destination address.