Abstract: In one embodiment, a method includes obtaining an indication that a state associated with a node is to be changed and preventing data from being received on a first link. The method also includes updating at least one selected from a group including an incoming interface check (IIC) table and an outgoing interface (OIF) table to reflect the state. The state indicates that a second link is to be activated. Finally, the method includes allowing the data to be received on the second link after updating either or both the IIC table and the OIF table and after the timer duration for the NULL value for IIC has expired.

Abstract: In one embodiment, a method includes setting a re-flood time to a non-zero first value. Update data that indicates a change to link data is received over a network interface from an updating node of multiple nodes on a multi-access segment connected to the interface. The change is to link data that indicates links on the updating node. It is determined whether an acknowledgment message is not received within the re-flood time from a particular node of the multiple nodes. If an acknowledgment message is not received within the re-flood time, then a multicast packet directed to the multiple nodes and including the change to the link data is sent over onto the segment. This method enables rapid response to failure of a primary node designated to ensure reliable flooding of link data.

Abstract: In one example embodiment, a system and method are shown that includes calculating a first SPF tree for a first device, the first SPF tree including a root node and a first child node, the first device being the root node of the first SPF tree. Additionally, the system and method may include calculating a second SPF tree for a second device that is a neighbor of the first device, the second SPF tree including a root node and a first child node, the second device being the root node of the second SPF tree. Further, the system and method may include building a set of interested nodes including the second device, if the first child node if the first SPF tree and the first child node of the second SPF tree are distinct.

Abstract: In one embodiment, a method includes receiving information on layer 2 topologies at a network device in a core network, mapping one or more Virtual Local Area Networks (VLANs) to the layer 2 topologies to provide differentiated services in said layer 2 topologies, defining multiple paths for each of the layer 2 topologies, and forwarding a packet received at the network device on one of the multiple paths. An apparatus and logic for providing differentiated services in layer 2 topologies is also disclosed.

Abstract: In one embodiment, a method includes receiving information on layer 2 topologies at a network device in a core network, mapping one or more Virtual Local Area Networks (VLANs) to the layer 2 topologies to provide differentiated services in said layer 2 topologies, defining multiple paths for each of the layer 2 topologies, and forwarding a packet received at the network device on one of the multiple paths. An apparatus for providing differentiated services in layer 2 topologies is also disclosed.

Abstract: A method is provided in one example embodiment and includes establishing a communication pathway between a first network node and a second network node coupled to a network; forming an adjacency to a new network node coupled to the network, where a designated intermediate system (DIS) election operation is executed after the adjacency is formed in order to determine that the new network node is a newly identified DIS for the network; and communicating a message advertising connectivity to both a previously identified DIS and the newly identified DIS, where the message is communicated during a specified time interval.

Abstract: A method and apparatus for routing data in a network is disclosed. A spoke router signals its intention to act as spoke in a new bit in Hello and database descriptor packets. A router acting as hub acknowledges the spoke request. Once the spoke router receives the hub's acknowledgement, it installs a default route to the hub router. Flooding is suppressed from hub to spoke. Instead of flooding, the hub router sends empty database descriptor packets so that no request is sent from spoke routers and any further change in the topology is not sent to spoke routers. This minimizes the flooding in this environment.

Abstract: In one embodiment, providing multi-layer address security incorporating Layer 2 Media Access Control (MAC) addresses and corresponding Layer 3 Internet Protocol (IP) addresses for host machines on a routed access network is provided.

Abstract: A checkpointing approach enables BGP peers to reduce the number of UPDATE messages that are exchanged and processed after a router restarts and to pause and suspend BGP sessions when mobile nodes leave a BGP domain. In an embodiment, a router is configured for receiving a BGP pause message from a mobile node; suspending interaction with the mobile node using BGP, including suspension of expiration of BGP sessions for lack of keepalive messages; receiving a BGP resume message from the mobile node, wherein the resume message comprises a checkpoint marker that identifies a last route update that the mobile node received before the suspending; resuming interaction with the mobile node using BGP; and determining and sending to the mobile node all BGP routes that originated after the checkpoint marker.

Abstract: The present invention elects an area border router from a plurality of potential area border routers by determining a full set of all areas attached to a router. A determination is made as to a full set of area pairs from the determined full set of areas. Routers are identified in a first area of the determined full set of areas that are reachable through an intra-area route in the first area, and routers are identified in a second area of the determined full set of areas that are reachable through an intra-area route in the second area. If there is a router that is unreachable through either an intra-area route in the first area or an intra-area route in the second area, then declare the first router to be an area border router, else new first and second areas are selected.

Abstract: In one embodiment, a Link State Advertisement (LSA) is received from a first router in a network at a second router in the network. The LSA advertises an address of an interface of the first router. The second router determines whether the LSA includes a transit-only identification that indicates the interface of the first router is a transit-only interface. If the LSA does not include a transit-only identification, the second router installs the advertised address of the interface of the first router in a Router Information Base (RIB) of the second router. If the LSA does include a transit-only identification, the second router declines to install the advertised address of the interface of the first router in the RIB of the second router.

Abstract: A data processing apparatus comprises instructions to perform sending and receiving one or more messages conforming to a network routing protocol, such as Open Shortest Path First (OSPF); obtaining one or more information elements that specify one or more capabilities of the apparatus; creating a particular routing protocol message comprising an opaque advertisement that includes the one or more information elements; and sending the particular message on one of the network interfaces. For example, a router or switch that implements a network routing protocol can use OSPF Opaque Link State Advertisements to advertise and discover services and capabilities of other routers or switches.

Abstract: A method of administering a plurality of routers in a computer network, comprising initializing a router in the plurality; receiving initial database description packets from at least first and second neighboring routers; processing the data description packet received from the first neighboring router; generating a request for link state advertisements from the first neighboring router; processing the database description packet received from the second neighboring router; if requesting link state advertisements from the second neighboring router that were not requested from the first neighboring router.

Abstract: A system for hiding transit-only interfaces in a network. When a routing system is advertising a transit-only interface, the advertisement is marked to indicate the address is a transit-only interface. A routing system receives the advertisement and detects the identifier of the transit-only interface and does not store the address in the Router Information Base of the routing system.

Abstract: In one embodiment, a method generally includes establishing a routing protocol peer relationship and a Bidirectional Forwarding Detection (BFD) session with a neighbor node, receiving a DOWN BFD event signal from the neighbor node, and maintaining a routing protocol adjacency down state following successful exchange of routing protocol packets with the neighbor node. An apparatus for maintaining protocol adjacency state with a forwarding failure is also disclosed.

Abstract: A method and apparatus for managing network communication that operate on the idea that if a new neighboring node is already reachable as represented in a shortest path data structure that the local node consults, there is no urgency in doing a full database synchronization between the local node and the neighboring node. The present invention delays database synchronization as long as possible to reduce unnecessary OSPF packets traversing communication links between nodes of the network. Since unsynchronized neighbors remain in 2-way state, OSPF updates are not flooded over the corresponding interfaces.

Abstract: A method and apparatus for sharing routing information include receiving first domain data that indicates domains of a first mobile router. A domain is a collection of routers that share uniform routing information at a particular level of detail. An inbound data packet is received from a second mobile router over a particular link. The inbound control plane packet lists second domain data that indicates domains of the second mobile router. The first domain data and the second domain data together include multiple domains. A particular domain is automatically selected from the first domain data and the second domain data. The second mobile router independently selects the same particular domain. The particular link is assigned to the particular domain; and routing information for the particular domain is shared between the first mobile router and the second mobile router over the particular link.

Abstract: In one embodiment, a method includes obtaining an indication that a state associated with a node is to be changed and preventing data from being received on a first link. The method also includes updating at least one selected from a group including an incoming interface check (IIC) table and an outgoing interface (OIF) table to reflect the state. The state indicates that a second link is to be activated. Finally, the method includes allowing the data to be received on the second link after updating either or both the IIC table and the OIF table and after the timer duration for the NULL value for IIC has expired.

Abstract: Techniques for detecting loops in routes that cross route information boundaries include receiving a control message at a first edge node on one side of the boundary that is connected to a different second edge node on another side of the boundary. The control message indicates a particular network address of a particular node that is reachable from the first edge node. Distinguisher data is determined that indicates if a node in the first collection can reach the first edge node without leaving the first collection. An advertising message is sent from the first edge node to the second edge node that includes route data that indicates the particular network address and the distinguisher data. Based on the distinguisher data, a testing edge node in the first collection can determine whether there is a loop comprising both an internal path and an external path to the first edge node.

Abstract: An ability to compress packets is announced from a customer edge router (CE) to other CEs through a routing protocol packet. An announcement of that ability is received from another CE through a routing protocol packet. A compression technique is then matched. The CE receives compression information from the other CE in a routing protocol packet, and determines that a compression technique identified therein matches any compression technique the CE is programmed to use. The CE then flags packets transmitted from/received by the CE to be compressed/decompressed according to the matched compression technique. Alternatively, the CE may match by transmitting compression information identifying a compression technique to the another CE in a routing protocol packet; the another CE receives the routing protocol packet and determines that a compression technique identified in the compression information of the routing protocol packet matches any compression technique the another CE is programmed to use.