Abstract: A system for providing a tree topology for a network having an interior gateway protocol. A first router receives a hello message from all connected routers in the network. The hello messages include tree topology information. The first router then uses the tree topology information to determine a parent of the router. The first router then establishes connections with directly connected routers at the same level in the tree topology. The first router also generates link messages that include all of the prefixes for children of the first router and broadcasts the link messages.

Abstract: A method of supporting a unidirectional link from a first router to a second router, the first and second routers existing in an area of a communication network, the method comprising: the second router receiving a hello packet from the first router; the second router determining that its topology information for the communication network is incomplete; the second router encapsulating an open shortest path first (OSPF) packet into an Opaque link state advertisement (LSA); and the second router flooding the Opaque LSA over the area.

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: 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: The present invention provides a method of determining whether database located on a first router is synchronized with the database located on a second router by performing a hash function on the values contained in a link state database to derive a SHA-1 digest value. In an embodiment, the digest value is based on LSA type. The digest value is exchanged initially during a database description packet swap between the first router and second router. If the digest values are the same, the databases are already synchronized. The routers thus skip the database description packet exchange of LSAs in the database and go directly to FULL state, indicating full synchronization between databases on the first and second router and announcing adjacency to each other. If the digest differs, normal database description packet exchange is performed as specified in OSPF.

Abstract: In an example embodiment, a method is provided that assigns a sequence value to a host. The host is identified by a host network layer address. After the assignment, the host network layer address and the sequence value are included in an advertisement for transmission. In another example embodiment, another method is provided. Here, a first sequence value associated with the host network layer address is received from a network device. In addition, a second sequence value associated with the same host network layer address is received from a different network device. The first sequence value is ranked relative to the second sequence value and data is transmitted to the network device based on the ranking.

Abstract: In one embodiment, detecting a host device on a port of a forwarder switch in a network, detecting a movement of the host device from a first forwarder switch to a second forwarder switch, and multicast broadcasting an updated device information for the host device to a convergence group switches and a proximity group switches, where the convergence group switches includes switches in the network that are not configured as forwarder switches, and the proximity group switches include forwarder switches grouped together based on radio proximity is provided.

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: 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: A method and apparatus are presented supporting shortest path first (SPF) routing of data packets over a network by establishing link-state data at an router. Link-state data indicates direct links between the router and a different router and establishes an adjacency relationship with the different node. Initial link-state data is stored at a first router. After the initial link-state data is stored, a hello message is received at the first router. The hello message indicates a direct connection with a different second router on one network segment. Based on the initial link-state data, it is determined whether establishing an adjacency relationship with the second router is sufficiently valuable. If not, then an adjacency relationship is not established with the second router in response to the hello message. A shortest path first routing for a data packet traversing the network is determined based on one or more adjacency relationships indicated in link-state data stored at the first router.

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.

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: 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: 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: A system for providing a tree topology for a network having an interior gateway protocol. A first router receives a hello message from all connected routers in the network. The hello messages include tree topology information. The first router then uses the tree topology information to determine a parent of the router. The first router then establishes connections with directly connected routers at the same level in the tree topology. The first router also generates link messages that include all of the prefixes for children of the first router and broadcasts the link messages.

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: A system for switching from a working path to a protected path when the working path becomes inoperable. In accordance with this system, point to multi-point adjacency is established between interfaces on two directly connected routing systems. This improves the speed at which the switch may occur.

Abstract: A SONET network terminated by routers includes working paths and backup paths. The routers pre-establishes in their link state data bases the links in both for both the working and backup paths. However, the links involved in the backup paths are given higher costs, then the links working paths, that the routers select only the links in the working path. If there is a failure in a link in a working path, an APS arrangement provides rapid switchover of the optical links so as to substitute one or more links in the corresponding backup path. This is accomplished by changing the relative costs of the working and backup links involved, so that the routers select the backup links for their routing tables.

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 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.