Abstract: In one embodiment, an apparatus includes a plurality of network site interfaces in communication with two or more networks, each of the networks associated with a different Virtual Routing and Forwarding (VRF) instance, and a processor configured for mapping the VRF instances to an Interior Gateway Protocol (IGP) adjacency and transmitting VRF information on the IGP adjacency along with a VRF identifier indicating the network associated with the VRF information. A method is also disclosed.

Abstract: Systems and methods for automatically controlling efficient operation of a plurality of network appliances operatively linked and networked to balance network traffic load across a plurality of network appliances that are selectively enabled. The system facilitating performance of the method includes at least a plurality of network appliances operatively connected to a switch and controlled by a network access control module. During system operation, at any given moment in time, the plurality network appliances operate in one of two modes, fully operational or stand-by. The network appliances of the plurality that are fully operational and thereby consuming full operational power depends upon the network traffic load at any given moment in time. The network appliances functioning in a stand-by mode consume low power levels which are sufficient to allow a network appliance in stand-by mode to receive a command signal directing it to switch from stand-by to full operational mode.

Abstract: A method and apparatus for preventing loops in a network with network devices operating a spanning tree protocol and network devices operating a link state routing protocol to prevent loops are disclosed. In one embodiment, a method includes receiving from one of the network devices operating a link state protocol, a link state routing synchronization packet at a first network device in communication with one of the network devices operating the spanning tree protocol, blocking at the first network device, boundary ports in communication with the network devices operating the spanning tree protocol, transmitting a link state routing synchronization acknowledgement packet at the first network device after the boundary ports are blocked, and performing a loop-free topology convergence process at the first network device.

Abstract: A method and system for preventing loops in a network including network devices operating different protocols for providing loop-free topology are disclosed. In one embodiment, a method includes receiving link state information at a network device operating a first protocol and in communication with a network device operating a second protocol, creating at least one tunnel to one or more other network devices operating the first protocol and in communication with a network device operating the second protocol, receiving a proposal, blocking designated boundary ports in communication with network devices operating the second protocol, and transmitting an agreement.

Abstract: In one embodiment, a method includes receiving at a network device designated as a secondary designated router or forwarder, an indication that a receiver wants to join a multicast group, transmitting a multicast join message in response to the received indication, and receiving multicast data from a source at the network device. If a primary designated router or forwarder is operating to forward the multicast data from the source to the receiver, the received multicast data is dropped. If a failure occurs at the primary designated router or forwarder, the received multicast data is forwarded to the receiver. An apparatus for fast multicast convergence at a secondary designated router or forwarder is also disclosed.

Abstract: A mechanism that provides congruent forwarding paths for unicast and multicast data traffic over a service provider core network includes issuing, by a receiver edge node, a request to join a multicast tree structure. A unicast path from the receiver edge node to a source node of the provider network is then established using a special message that contains an identifier. The identifier allows the unicast path through the core network to be aligned with the multicast tree structure. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: A method and apparatus for fast reroute of multicast data are disclosed. In one embodiment, a method includes transmitting a multicast join message from a receiver towards a source on a primary path and transmitting an alternate multicast join message from the receiver towards the source on a backup path. Data packets are then received from the primary and backup paths. The method further includes operating in a first mode wherein the data packets received from the primary path are accepted and the data packets received from the backup path are dropped, and switching to a second mode wherein the data packets received from the backup path are accepted, upon detecting a failure in the primary path.

Abstract: Systems and methods for implementing a bidirectional multicast protocol with two types of join messages are disclosed. The two types of join messages, upstream joins and downstream joins, are used to control the Reverse Path Forwarding (RPF) interface is added to the outgoing interface list for a particular multicast group, which in turn controls when multicast packets will be forwarded to the rendezvous point. One method involves receiving a multicast packet addressed to multicast group G. The method inhibits the multicast packet from being forwarded via the RPF interface, unless the outgoing interface list corresponding to the multicast group G already identifies the RPF interface. The RPF interface can be added to the outgoing interface list in response to reception of a downstream join message via the RPF interface, as well as in response to monitoring, via the RPF interface, an upstream join message on a shared network segment.

Abstract: A method of signaling in a computer network uses interception by a network device of a message transmitted by a client computer to a server. The message contains a Universal Resource Locator (URL), the URL having a reserved port designation. The network device parses the URL and intercepts the message in response to finding the reserved port designation in the URL. The network device executes a command, where the command is carried in a field of the intercepted message. The client computer receives the URL having the reserved port designation in a HTML file transmitted to the client computer by the server. The message containing the URL is transmitted by the client computer in response to a user requesting a resource displayed in a web page displayed by the client computer.

Abstract: A network packet is encapsulated and has at least one field in the header of the encapsulation. A multicast delivery tree is written into a field of the encapsulating header. A method for operating a router to use the multicast delivery tree encapsulated in the header of the network packet has the following steps. The router receives a packet from a computer network, the packet having an encapsulated field. The router then reads a multicast delivery tree from the encapsulated field, the multicast delivery tree having a route to each of a plurality of destination stations. Then, the router forwards the packet to an address selected in response to the multicast delivery tree.

Abstract: In one embodiment, a method includes receiving a multicast join message at a node having a plurality of interfaces, identifying the interface at which the join message was received, and selecting one or more of the interfaces to transmit the join message based on whether the join message was received on a ring interface. If the join message was received on one of the ring interfaces, the join message is transmitted on another of the interfaces. If the join message was not received on one of the ring interfaces, the join message is transmitted on both of the ring interfaces. The method further includes receiving multicast data and transmitting the multicast data on the interface at which the join message was received.

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: Various systems and methods are disclosed for performing multicast routing over unidirectional links. For example, one method involves maintaining a multicast adjacency state, which is associated with an interface that is coupled to receive messages from a network device via a unidirectional link. The multicast adjacency state identifies a network address of the network device. The method also involves sending a multicast protocol control message to the network device via a bidirectional path. The destination address of the network multicast protocol control message is the network address in the multicast adjacency state.

Abstract: In one embodiment, a method includes receiving a multicast join message at a node having a plurality of interfaces, identifying the interface at which the join message was received, and selecting one or more of the interfaces to transmit the join message based on whether the join message was received on a ring interface. If the join message was received on one of the ring interfaces, the join message is transmitted on another of the interfaces. If the join message was not received on one of the ring interfaces, the join message is transmitted on both of the ring interfaces. The method further includes receiving multicast data and transmitting the multicast data on the interface at which the join message was received.

Abstract: Various systems and methods are disclosed for performing multicast routing over unidirectional links. For example, one method involves maintaining a multicast adjacency state, which is associated with an interface that is coupled to receive messages from a network device via a unidirectional link. The multicast adjacency state identifies a network address of the network device. The method also involves sending a multicast protocol control message to the network device via a bidirectional path. The destination address of the network multicast protocol control message is the network address in the multicast adjacency state.

Abstract: In one embodiment, a method includes receiving at a network device designated as a secondary designated router or forwarder, an indication that a receiver wants to join a multicast group, transmitting a multicast join message in response to the received indication, and receiving multicast data from a source at the network device. If a primary designated router or forwarder is operating to forward the multicast data from the source to the receiver, the received multicast data is dropped. If a failure occurs at the primary designated router or forwarder, the received multicast data is forwarded to the receiver. An apparatus for fast multicast convergence at a secondary designated router or forwarder is also disclosed.

Abstract: In one embodiment, an apparatus includes one or more internal interfaces in communication with one or more network devices in a first network site through a Layer 2 link, an overlay interface in communication through a Layer 3 link with a core network connected to one or more other network sites, and a table mapping addresses for network devices in the other network sites to addresses of edge devices in the same network site as the network device. The apparatus further includes a processor operable to encapsulate a packet received at one of the internal interfaces and destined for one of the network devices in the other network sites, with an IP header including a destination address of the edge device mapped to the destination network device, and forward the encapsulated packet to the core network.

Abstract: A method and system for translation of virtual private network (VPN) addresses over a provider network are disclosed. The method includes creating a multipoint tunnel extending between customer edge routers in a VPN network and over the provider network. The multipoint tunnel is identified with a multicast address and multicast packets are sent over the tunnel to identify tunnel endpoints at customer edge routers within the VPN. The method further includes converting, at one of the customer edge routers, a VPN join message to a provider join message and sending it over the provider network.

Abstract: A method and system for preventing loops in a network including network devices operating different protocols for providing loop-free topology are disclosed. In one embodiment, a method includes receiving link state information at a network device operating a first protocol and in communication with a network device operating a second protocol, creating at least one tunnel to one or more other network devices operating the first protocol and in communication with a network device operating the second protocol, receiving a proposal, blocking designated boundary ports in communication with network devices operating the second protocol, and transmitting an agreement.

Abstract: A method and apparatus for fast reroute of multicast data are disclosed. In one embodiment, a method includes transmitting a multicast join message from a receiver towards a source on a primary path and transmitting an alternate multicast join message from the receiver towards the source on a backup path. Data packets are then received from the primary and backup paths. The method further includes operating in a first mode wherein the data packets received from the primary path are accepted and the data packets received from the backup path are dropped, and switching to a second mode wherein the data packets received from the backup path are accepted, upon detecting a failure in the primary path.