Abstract: In some examples, a network device of a network comprises a first component configured to store a plurality of next hop instructions corresponding to respective logical or physical network structures of the network. The network device also comprises a second component configured to send, to the first component, a message that identifies an association of the plurality of next hop instructions, wherein the first component is further configured to modify, in response to receiving the message, each of the plurality of next hop instructions.

Abstract: A system for synchronizing packet forwarding information includes a control processor configured to implement a control plane to generate first forwarding information and transfer the first forwarding information to an active forwarding table of a network processor. The system also includes a network processor configured to implement a forwarding plane to receive packets and use the first forwarding information in the active forwarding table to forward the received packets to one or more network devices. After the control plane is restarted, the control processor is further configured to use the restarted control plane to generate second forwarding information and incrementally update the first forwarding information in the active forwarding table with the second forwarding information while the network processor's forwarding plane continues to forward traffic.

Abstract: In one embodiment, correlating label switched paths of a pseudowire includes receiving a first message at a second label switching router. The first message is sent from a first label switching router and includes a pseudowire identifier and a first label switched path identifier. The pseudowire identifier identifies a pseudowire, and the first label switched path identifier identifies a first label switched path that implements the pseudowire. A second message is sent from the second label switching router to the first label switching router. The second message comprises the pseudowire identifier and a second label switched path identifier. The second label switched path identifier identifies a second label switched path that implements the pseudowire.

Abstract: In one embodiment, informing nodes of traffic management resource availability includes establishing whether there is an available traffic management resource at a first node, where a traffic management resource tracks usage of bandwidth by a tunnel at the first node. Whether there is an available traffic management resource is recorded in a traffic management link attribute. The traffic management link attribute is sent to second nodes to inform the second nodes of whether there is an available traffic management resource at the first node.

Abstract: In one embodiment, informing nodes of traffic management resource availability includes establishing whether there is an available traffic management resource at a first node, where a traffic management resource tracks usage of bandwidth by a tunnel at the first node. Whether there is an available traffic management resource is recorded in a traffic management link attribute. The traffic management link attribute is sent to second nodes to inform the second nodes of whether there is an available traffic management resource at the first node.

Abstract: In one embodiment, correlating label switched paths of a pseudowire includes receiving a first message at a second label switching router. The first message is sent from a first label switching router and includes a pseudowire identifier and a first label switched path identifier. The pseudowire identifier identifies a pseudowire, and the first label switched path identifier identifies a first label switched path that implements the pseudowire. A second message is sent from the second label switching router to the first label switching router. The second message comprises the pseudowire identifier and a second label switched path identifier. The second label switched path identifier identifies a second label switched path that implements the pseudowire.

Abstract: In one embodiment, informing nodes of traffic management resource availability includes determining a number of available traffic management resources at a first node, where a traffic management resource tracks usage of bandwidth by a tunnel at the first node. The number of available traffic management resources is recorded in a link-state advertisement. The link-state advertisement is sent to one or more second nodes.

Abstract: In accordance with the teachings of the present invention, a system and method for synchronizing packet forwarding information is provided. In a particular embodiment, the system includes a control processor configured to implement a control plane to generate first forwarding information and transfer the first forwarding information to an active forwarding table of a network processor. The system also includes a network processor configured to implement a forwarding plane to receive packets and use the first forwarding information in the active forwarding table to forward the received packets to one or more network devices. After the control plane is restarted, the control processor is further configured to use the restarted control plane to generate second forwarding information and incrementally update the first forwarding information in the active forwarding table with the second forwarding information while the network processor's forwarding plane continues to forward traffic.

Abstract: In highly-available Open Shortest Path First (OSPF) routing in a network, the dynamic state of a backup OSPF instance in a router is synchronized with the dynamic state of an active OSPF instance using explicit message transmission from the active instance to the backup instance. After this, the dynamic state synchronization of the backup OSPF instance is maintained using a combination of explicit message updates from the active OSPF instance together with a message flow-through mechanism. In the event of fail-over of the active OSPF instance, then the router recovers seamlessly without reconfiguring or interrupting traffic among peer routers in the network, by functionally substituting the synchronized backup OSPF instance for the active OSPF instance, such that the backup OSPF instance establishes itself as the new active OSPF instance.

Abstract: The HA IS-IS system provides a redundant backup IS-IS protocol instance that can seamlessly assume the function of the active IS-IS instance in the event of active MCP failure. Once the backup is online, the active synchronizes its global, interface, adjacency, neighbor, and LSP system state information. In the ongoing synchronization phase, the active and the backup maintain synchronization using a combination of explicit message updates from active to backup together with message flow-through. In the recovery phase, the operating system detects the failure of the active and notifies the backup, which assumes the active function as a standalone system without reconfiguring or interrupting traffic among peer network routers, and starts computing forwarding tables and updating routing tables.

Abstract: Virtual routers within a single physical router share a centralized data plane containing a centralized switch fabric and a plurality of physical network interfaces, each assigned to only one virtual router. Using a logical cut-through device between a pair of virtual routers designated respectively client and server, packet forwarding information from the server is imported into the client, which creates, allocates, and maintains a data structure for the imported information, which then resides on the client interfaces. This imported forwarding information is then integrated into a single forwarding table that is used to recognize an incoming packet at the client and forward it appropriately out through a server interface with a single packet forwarding decision in a single transit through the switch fabric. Within a physical router, a client virtual router can communicate with multiple servers and can concurrently function as a server to multiple clients.

Abstract: Virtual routers within a single physical router share a centralized data plane containing a centralized switch fabric and a plurality of physical network interfaces, each assigned to only one virtual router. Using a logical cut-through device between a pair of virtual routers designated respectively client and server, packet forwarding information from the server is imported into the client, which creates, allocates, and maintains a data structure for the imported information, which then resides on the client interfaces. This imported forwarding information is then integrated into a single forwarding table that is used to recognize an incoming packet at the client and forward it appropriately out through a server interface with a single packet forwarding decision in a single transit through the switch fabric. Within a physical router, a client virtual router can communicate with multiple servers and can concurrently function as a server to multiple clients.

Abstract: The HA IS-IS system provides a redundant backup IS-IS protocol instance that can seamlessly assume the function of the active IS-IS instance in the event of active MCP failure. Once the backup is online, the active synchronizes its global, interface, adjacency, neighbor, and LSP system state information. In the ongoing synchronization phase, the active and the backup maintain synchronization using a combination of explicit message updates from active to backup together with message flow-through. In the recovery phase, the operating system detects the failure of the active and notifies the backup, which assumes the active function as a standalone system without reconfiguring or interrupting traffic among peer network routers, and starts computing forwarding tables and updating routing tables.

Abstract: In highly-available Open Shortest Path First (OSPF) routing in a network, the dynamic state of a backup OSPF instance in a router is synchronized with the dynamic state of an active OSPF instance using explicit message transmission from the active instance to the backup instance. After this, the dynamic state synchronization of the backup OSPF instance is maintained using a combination of explicit message updates from the active OSPF instance together with a message flow-through mechanism. In the event of fail-over of the active OSPF instance, then the router recovers seamlessly without reconfiguring or interrupting traffic among peer routers in the network, by functionally substituting the synchronized backup OSPF instance for the active OSPF instance, such that the backup OSPF instance establishes itself as the new active OSPF instance.