Abstract: In general, techniques are described for providing extended administrative groups in networks. A network device comprising an interface and a control unit may implement the techniques. The interface receives a routing protocol message that advertises a link. This message includes a field for storing first data associated with the link in accordance with the routing protocol. The field is defined by the routing protocol as a field having a different function from an administrative group field defined by the same routing protocol. The control unit determines that this field has been repurposed to store second data, wherein this second data specifies an extended administrative group for the link different from those that may be specified by the administrative group field. The control unit then updates routing information to associate the advertised link with the extended administrative group and performs path selection to select paths based on the updated routing information.

Abstract: A connection between network nodes in a communication network is backed up. A failover switched path such as a label-switched path (LSP) is created starting at a first network node of a connection and ending at the second node of the connection, while bypassing the protected connection. In the event of connection failure, data is transmitted through the failover switched path (e.g., LSP). A network operator can selectively protect different types of data by using filters that bind one or more types of traffic received over one or more interfaces to different failover switched paths (LSPs).

Abstract: Techniques are described for scaling Multiprotocol Label Switching (MPLS) across areas of an autonomous system using a labeled interior Border Gateway Protocol (iBGP). A method includes executing a first label distribution protocol at a border node at a border between two of a plurality of interior gateway protocol (IGP) areas of a single autonomous system (AS), and exchanging label distribution messages using the first label distribution protocol to establish a first intra-area label switched path (LSP) within a first one of IGP areas. The method also includes executing a labeled interior border gateway protocol at the border node, and exchanging label distribution messages using the labeled interior border gateway protocol to establish a hierarchical inter-area LSP that runs over the previously established first intra-area LSP, wherein the hierarchical inter-area LSP extends across the plurality of IGP areas of the AS.

Abstract: A router receives a control plane message for constructing a first LSP to a destination within a network that conforms to a first type of LSP. The control plane message includes a label for the first LSP and an identifier that identifies a first type of data traffic. The router receives a second control plane message for constructing a second LSP that conforms to the first type of LSP. The second control plane message includes a label for the second LSP and an identifier that identifies a second type of data traffic. The router installs forwarding state in accordance with policies that associate the first and second types of data traffic with different LSPs of a second type that each traverse different paths through the network, and forwards packets via the interface in accordance with the installed forwarding state.

Abstract: In general, techniques are described for dynamically configuring cross-domain pseudowires (PWs). A network device positioned between a first domain and a second domain of a computer network may implement the techniques. The intermediate network device comprises at least one interface and an LDP module, a transformation module and a routing protocol module. The interface receives a label distribution protocol (LDP) message that includes data for configuring a cross-domain PW from a first provider edge (PE) device of the first domain. The LDP module parses the received LDP message to extract the cross-domain PW configuration data. The translation module transforms the extracted data to conform to routing protocol extensions for advertising the cross-domain PW configuration data. The routing protocol module forms a routing protocol message that includes the transformed data. The interface outputs the routing protocol message to the second intermediate device of the second domain to establish the cross-domain PW.

Abstract: In some embodiments, an apparatus comprises a core network node configured to be operatively coupled to a set of network nodes. The core network node is configured to receive a broadcast signal from a network node from the set of network nodes, which is originated from a host device operatively coupled to the network node. The broadcast signal is sent via a tunnel from the network node to the core network node, such that other network nodes that are not included in the tunnel do not receive the broadcast signal. The core network node is configured to retrieve control information associated with the broadcast signal without sending another broadcast signal, and then send the control information to the network node.

Abstract: In some embodiments, an apparatus includes a network node operatively coupled within a network. The network node is configured to send a first authentication message upon boot up, and receive, in response to the first authentication message, a second authentication message configured to be used to authenticate the network node. The network node is configured to send a first discovery message, and receive, based on the first discovery message, a second discovery message configured to be used by the network node to identify an address of the network node and an address of a core network node within the network. The network node is configured to set up a control-plane tunnel to the core network node based on the address of the network node and the address for the core network node and receive configuration information from the core network node through the control-plane tunnel.

Abstract: In general, techniques are described for providing extended administrative groups in networks. A network device comprising an interface and a control unit may implement the techniques. The interface receives a routing protocol message that advertises a link. This message includes a field for storing first data associated with the link in accordance with the routing protocol. The field is defined by the routing protocol as a field having a different function from an administrative group field defined by the same routing protocol. The control unit determines that this field has been repurposed to store second data, wherein this second data specifies an extended administrative group for the link different from those that may be specified by the administrative group field. The control unit then updates routing information to associate the advertised link with the extended administrative group and performs path selection to select paths based on the updated routing information.

Abstract: A first network device creates a protection path to a second network device associated with a first service site, and creates a pseudowire between the first service site and a second service site via the first network device and the second network device. The first network device also detects a failure between the first network device and the first service site, and forwards traffic, provided by the pseudowire between the first service site and the second service site, via the protection path. The second network device uses the traffic on the protection path as a trigger to activate a link between the second network device and the first service site.

Abstract: This disclosure describes techniques for protecting an endpoint of a label switched path. In one embodiment, a system includes an ingress router, a primary egress router, backup router, and a point of local repair (PLR) router. The ingress router, the PLR router, and the first egress router form a first label switched path. The backup router provides protection for the primary egress router such that the backup router provides routing services for the first egress router when the first egress router is not available. The primary egress router and the backup router share an anycast IP address. The backup router advertises a route to reach the primary egress router, but upon receiving a packet intended for the primary egress router, the backup router identifies the destination of the packet and forwards the packet to the destination instead of the primary egress router along a different route.

Abstract: A first network device creates a protection path to a second network device associated with a first service site, and creates a pseudowire between the first service site and a second service site via the first network device and the second network device. The first network device also detects a failure between the first network device and the first service site, and forwards traffic, provided by the pseudowire between the first service site and the second service site, via the protection path. The second network device uses the traffic on the protection path as a trigger to activate a link between the second network device and the first service site.

Abstract: Virtual Private Networks (VPNs) are supported in which customers may use popular internet gateway protocol (IGPs) without the need to convert such IGPs, running on customer devices to a single protocol, such as the border gateway protocol (BGP). Scaling problems, which might otherwise occur when multiple instances of an IGP flood link state information, are avoided by using a flooding topology which is smaller than a forwarding topology. The flooding topology may be a fully connected sub-set of the forwarding topology.

Abstract: Label distribution protocol (LDP) signaled label-switched paths (LSPs) are supported without requiring information about remote autonomous systems (ASs) to be injected into the local interior gateway protocol (IGP). This may be done by (i) decoupling a forwarding equivalency class (FEC) element from the routing information, and (ii) specifying a next hop on which the FEC relies. An LDP messaging structure (e.g., an LDP type-length-value (TLV)) that includes a label, FEC information (e.g., a host address or prefix of an egress LSR of the LSP) and a next hop (e.g., a host address or prefix of a border node, such as an AS border router (ASBR)) may be provided. This messaging structure may be included in one or more of (a) label mapping messages, (b) label withdraw messages, and (c) label release messages.

Abstract: Methods and apparatus for allowing routers in an autonomous system to implement LDP and RSVP at the same time. RSVP can be used in the network core with LDP being used in network regions surrounding the core. LDP LSPs are tunneled through the RSVP network core using RSVP LSPs and label stacking techniques. During route selection LDP LSPs which use an RSVP LSP tunnel are preferred over alternative LDP LSPs having an equal cost associated with them to create a preference for traffic engineered routes.

Abstract: A connection between network nodes in a communication network is backed up. A failover switched path such as a label-switched path (LSP) is created starting at a first network node of a connection and ending at the second node of the connection, while bypassing the protected connection. In the event of connection failure, data is transmitted through the failover switched path (e.g., LSP). A network operator can selectively protect different types of data by using filters that bind one or more types of traffic received over one or more interfaces to different failover switched paths (LSPs).

Abstract: A connection between network nodes in a communication network is backed up. A failover label-switched path (LSP) is created starting at a first network node of a connection and ending 5 at the second node of the connection, while bypassing the protected connection. In the event of connection failure, data is transmitted through the failover LSP. A network operator can selectively protect different types of data by using filters that bind one or more types of traffic received over one or more interfaces to different failover LSPs.

Abstract: A router comprises an interface for receiving packets, wherein the packets include Multiprotocol Label Switching (MPLS) labels having the same label value that corresponds to an MPLS label switched path (LSP), and wherein each of the MPLS packets includes MPLS experimental (EXP) bits defined to identify a class of service to which the respective packet belongs. The router is a transit router along the MPLS LSP, and further includes a control unit that, for each of the packets, accesses forwarding information to determine whether to forward the packet along the LSP or to redirect the packet along a second LSP based on the classes of service specified in the EXP bits. The router receives policies via a user interface, and applies the policies to index into the forwarding information to select a forwarding entry, wherein the index is responsive to the label value in combination with the EXP bits.

Abstract: The invention is directed to techniques for failsafe management of periodic communications between network devices. A first network device, for example, establishes with a second network device a first response interval by which the first device responds to a message received from the second device. Prior to commencing a software upgrade, the first device determines whether the event requires an interval of time during which the first device cannot respond to the message within the established first response interval. Based on the determination and prior to commencing the upgrade, the first device establishes with the second device a second response interval that equals or exceeds the first response interval. Upon completion of the event, the first device establishes with the second device a third response interval. The first network device therefore may automatically adjust response intervals to accommodate upgrades that may cause unnecessary thrashing.

Abstract: The label distribution protocol (LDP) is extended to set up a point to multi-point (P2MP) label switched path (LSP) across a computer network from a source network device to one or more destination network devices. LDP is extended to create a P2MP label map message containing a label and a P2MP forwarding equivalence class (FEC) element having a root node address and an identifier. The P2MP FEC element may, for example, associate an address of the root node of the P2MP LSP with an opaque identifier. The P2MP FEC element uniquely identifies the P2MP LSP. The P2MP FEC element may be advertised with a label in a P2MP label map message. A source network device or the destination network devices may initiate setup and teardown of the P2MP LSP. The P2MP label map messages may be propagated from the destination network devices to the source network device.

Abstract: Techniques are described for performing non-revertive failover with network devices. A network device comprising a control unit and interface cards receives routing information protocol (RIP) updates each having a metric value. The control unit signals bidirectional forwarding detection (BFD) sessions based on the metric values of each of the RIP updates with, for example, a media gateway. The control unit also selectively installs a RIP route based on the metric values. The media gateway monitors the BFD sessions, and upon failure of an active BFD session, indicates the network device to perform non-revertive failover by sending a revised plurality of RIP updates. The network device performs non-revertive failover according to the revised plurality of RIP updates. Because of the flexibility of BFD, the network device need not revert back to a previous RIP route, therefore curtailing excessive failover.