Abstract: One embodiment of the invention provides a method of operating a switch in a communications network. The method includes storing a set of routings for each port in the switch. When a packet is received at a port in the switch, the set of routings corresponding to the port at which the packet was received is accessed. A port from which to forward the packet from the switch is determined in accordance with the set of routings. The packet is then duly forwarded over the network from the port as determined by the routings.

Abstract: One embodiment of the invention provides a method of handling an incoming packet at a node in a network. The method includes associating at least one source identifier with a link into the node. A packet is then received at the node over the link, and a source identifier is extracted from the received packet. The extracted source identifier is compared with the source identifier(s) associated with the link in order to authenticate the packet.

Abstract: One embodiment of the invention provides apparatus and a method for handling an incoming packet at a port in a network. The port belongs to one or more partitions, and at least one service level is associated with each of the partitions. When a packet is received at the port, a partition key and a service level are extracted from the packet. The extracted partition key is used to determine the partition to which the received packet belongs. The service level extracted from the packet is then compared against the service level(s) associated with the determined partition in order to authenticate the packet. In another embodiment, the service level is correlated against a destination identifier from the packet instead of the partition key.