Abstract: A network device includes a memory, a routing engine and a forwarding engine. The memory stores a forwarding table and the routing engine constructs a first composite next hop that includes multiple next hops, where each of the multiple next hops represents an action to be taken on a data unit as it transits the network device or represents another composite next hop, and where the first composite next hop specifies a function to be performed on the plurality of next hops. The routing engine further stores the composite next hop in an entry of the forwarding table. The forwarding engine retrieves the composite next hop from the forwarding table, and forwards a data unit towards one or more network destinations based on the composite next hop.

Abstract: A router maintains routing information including (i) route data representing destinations within a computer network, (ii) next hop data representing interfaces to neighboring network devices, and (iii) indirect next hop data that maps a subset of the routes represented by the route data to a common one of the next hop data elements. In this manner, routing information is structured such that routes having the same next hop use indirect next hop data structures to reference common next hop data. In particular, in response to a change in network topology, the router need not change all of the affected routes, but only the common next hop data referenced by the intermediate data structures. This provides for increased efficiency in updating routing information after a change in network topology, such as link failure.

Abstract: A provider edge device, associated with a virtual private local area network service (VPLS) system, includes a memory to store instructions to implement a pseudowire mechanism to receive a first data frame from a source customer edge (CE) device associated with the VPLS system, incorporate the first data frame into a first VPLS packet, determine whether the source CE device is a single-homed CE device or a multi-homed CE device, and incorporate, into the first VPLS packet, a first pseudowire label, if the source CE device is a single-homed CE device, and incorporate, into the first VPLS packet, a second pseudowire label, different from the first pseudowire label, if the source CE device is a multi-homed CE device; and a processor to execute the instructions.

Abstract: A route for a data unit through a network may be defined based on a number of next hops. Exemplary embodiments described herein may implement a router forwarding table as a chained list of references to next hops. In one implementation, a device includes a forwarding table that includes: a first table configured to store, for each of a plurality of routes for data units in a network, a chain of links to next hops for the routes; and a second table configured to store the next hops. The device also includes a forwarding engine configured to assemble the next hops for the data units based on using the chain of links in the first table to retrieve the next hops in the second table and to forward the data units in the network based on the assembled next hops.

Abstract: A layer 2 transport network, and components thereof, supporting virtual network functionality among customer edge devices. Virtual private network configuration can be accomplished with merely local intervention by preprovisioning extra channel (or circuit) identifiers at each customer edge device and by advertising label base and range information corresponding to a list of channel (or circuit) identifiers.

Abstract: In general, principles of the invention relate to techniques for detecting data plane failures in Multi-Protocol Label Switching (MPLS) Label-Switched Paths (LSPs) that may be tunneled over one or more other LSPs. More specifically, the techniques described herein allow for testing connectivity of an LSP that is tunneled through at least one other LSP, and testing connectivity of an inter-autonomous system LSP. For example, a method comprises providing, with an intermediate label-switching router (LSR) of an LSP, instructions to an ingress LSR of the LSP to modify a forwarding equivalence class (FEC) stack of MPLS echo request packets. The intermediate LSR may provide the instructions within an MPLS echo reply packet.

Abstract: A provider edge (PE) device, associated with a virtual private local area network service (VPLS) system, receives a first data frame from a source customer edge (CE) device associated with the VPLS system. The PE device further incorporates the first data frame into a first VPLS packet and determines whether the source CE device is a single-homed CE device or a multi-homed CE device. The PE device incorporates, into the first VPLS packet, a first pseudowire label when the source CE device is the single-homed CE device. The PE device incorporates, into the first VPLS packet, a second pseudowire label, when the source CE device is the multi-homed CE device. The second pseudowire label is different from the first pseudowire label.

Abstract: In general, techniques are described for summarizing label mappings and thereby enabling longest-prefix match within Multi-Protocol Label Switching (MPLS) networks. More specifically, a first router included within a first area of a network comprises a control unit that maintains a label space defining labels available for mapping to a plurality of addresses assigned to network devices within the network. The control unit reserves a contiguous set of the labels of the label space and maps the contiguous set of labels to first area addresses. The first area addresses include those addresses of the plurality of addresses available for assignment to network devices within the first area. The first router also includes an interface card that transmits, to a second router of a second area of the network, an advertisement that advertises a summarized version of the mapping between the contiguous set of labels and the first area addresses.

Abstract: A method and a network device for enabling communication between unnumbered interfaces are provided. A device level address may be assigned to a network device. The network device may announce the assigned device level address to a neighboring network device over a link. A corresponding device level address associated with the neighboring network device may be received over the link. A route may be stored including the received device level address associated with the neighboring network device and the link. In some implementations, the announcement of the assigned device level address is performed during protocol configuration.

Abstract: A network device receives a packet with a multicast nexthop identifier, and creates a mask that includes addresses of egress packet forwarding engines, of the network device, to which to provide the packet. The network device divides the mask into two portions, generates two copies of the packet, provides a first portion of the mask in a first copy of the packet, and provides a second portion of the mask in a second copy of the packet. The network device also forwards the first copy of the packet to an address of a first egress packet forwarding engine provided in the first portion of the mask, and forwards the second copy of the packet to an address of a second egress packet forwarding engine provided in the second portion of the mask.

Abstract: Network devices in a multicast network exchange multicast optimization data to improve efficiency of multicasting in the network. A protocol, e.g., a routing protocol or a multicast protocol, may be extended to allow the network devices to exchange the multicast optimization data. Alternatively, a separate protocol may be established for exchanging MOD. A network device may receive a message from an upstream device located between the device and a source for a multicast group, wherein the message includes multicast optimization data that specifies at least one criterion for selecting an upstream device. The device may use the data to intelligently select an optimal upstream device for receiving multicast using any of a variety of criteria to rank the upstream routers, such as minimization of multicast traffic duplication, load balancing current bandwidth levels, and avoiding paths experiencing communication delays.

Abstract: A method and apparatus for switching a data packet between a source and destination in a network. The data packet includes a header portion and a data portion. The header portion includes routing information for the data packet. The method includes defining a data path in the router comprising a path through the router along which the data portion of the data packet travels and defining a control path comprising a path through the router along which routing information from the header portion travels. The method includes separating the data path and control path in the router such that the routing information can be separated from the data portion allowing for the separate processing of each in the router. The data portion can be stored in a global memory while routing decisions are made on the routing information in the control path.

Abstract: Techniques are describe for establishing an overall label switched path (LSP) for load balancing network traffic being sent across a network using the a resource reservation protocol such as Resource Reservation Protocol with Traffic Engineering (RSVP-TE). The techniques include extensions to the RSVP-TE protocol that enable a router to send Path messages for establishing a tunnel that includes a plurality of sub-paths for the overall LSP. The tunnel may comprise a single RSVP-TE Label Switched Path (LSP) that is configured to load balance network traffic across different sub-paths of the RSVP-TE LSP over the network.

Abstract: Techniques are describe for establishing an overall label switched path (LSP) for load balancing network traffic being sent across a network using the a resource reservation protocol such as Resource Reservation Protocol with Traffic Engineering (RSVP-TE). The techniques include extensions to the RSVP-TE protocol that enable a router to send Path messages for establishing a tunnel that includes a plurality of sub-paths for the overall LSP. The tunnel may comprise a single RSVP-TE Label Switched Path (LSP) that is configured to load balance network traffic across different sub-paths of the RSVP-TE LSP over the network.

Abstract: A method and apparatus for switching a data packet between a source and destination in a network. The data packet includes a header portion and a data portion. The header portion includes routing information for the data packet. The method includes defining a data path in the router comprising a path through the router along which the data portion of the data packet travels and defining a control path comprising a path through the router along which routing information from the header portion travels. The method includes separating the data path and control path in the router such that the routing information can be separated from the data portion allowing for the separate processing of each in the router. The data portion can be stored in a global memory while routing decisions are made on the routing information in the control path.

Abstract: The disclosure is directed to techniques for automatically establishing an inter-autonomous system (AS) virtual private local area network service (VPLS) across a first AS and a second AS with improved scaling of pseudowires (PWs) between the first AS and the second AS. The techniques include extending the control plane of a border device to include a location table that records AS location information for the network devices that belong to the inter-AS VPLS. The techniques also include updating a medium access control (MAC) table in the data plane of the border device based on the location table to maintain a scalable number of PWs between the first AS and the second AS for the inter-AS VPLS. In some cases, the techniques may be used by border devices in both a first AS and a second AS to signal a single PW between the first AS and the second AS.

Abstract: Techniques are described for testing connectivity to unnumbered interfaces of a target device. For example, a software utility and protocol are described that allows an administrator to specify a logical offset that may be internally resolved by the target device to one of a plurality of unnumbered interfaces during the test. Similarly, the administrator may specify an offset that may be internally resolved by the source device to one of a plurality of unnumbered interfaces from which the connectivity test is to originate. The source device may send enhanced request packets and receive enhanced reply packets specifying the source unnumbered interface and the destination unnumbered interface between which connectivity is to be tested. In this manner, an administrator may test for connectivity of particular interfaces even where internet protocol (IP) addresses or other identifiers for the interfaces are not externally known.

Abstract: Loop detection information, such as information associated with the Spanning Tree Protocol (STP), is synchronized within virtual private networks. A routing protocol, such as the Border Gateway Protocol (BGP), is extended in a manner that allows STP information or other loop detection information to be opaquely communicated between routing devices across an intermediate network. These techniques may, for example, be useful in environments where Virtual Private LAN Service (VPLS) is run through one or more intermediate networks.

Abstract: A layer 2 transport network, and components thereof, supporting virtual network functionality among customer edge devices. Virtual private network configuration can be accomplished with merely local intervention by preprovisioning extra channel (or circuit) identifiers at each customer edge device and by advertising label base and range information corresponding to a list of channel (or circuit) identifiers.

Abstract: A provider edge device, associated with a virtual private local area network service (VPLS) system, includes a memory to store instructions to implement a pseudowire mechanism to receive a first data frame from a source customer edge (CE) device associated with the VPLS system, incorporate the first data frame into a first VPLS packet, determine whether the source CE device is a single-homed CE device or a multi-homed CE device, and incorporate, into the first VPLS packet, a first pseudowire label, if the source CE device is a single-homed CE device, and incorporate, into the first VPLS packet, a second pseudowire label, different from the first pseudowire label, if the source CE device is a multi-homed CE device; and a processor to execute the instructions.