Abstract: In one embodiment, an access component of a local network edge device receives traffic, and generates a frame for the traffic that includes a remote context label that identifies an access component of the remote network edge device to which the traffic is to be forwarded upon arrival at the remote network edge device, and a virtual circuit label corresponding to a particular virtual service of the traffic. The local network edge device forwards the frame towards the remote network edge device. In another embodiment, the frame may be received at a core component of the remote network edge device, an in response to the remote context label identifying an access component of the remote network edge device, forwarded to the access component, which determines the particular virtual service, and forwards the traffic from the frame out the access component towards an endpoint for the traffic.

Abstract: In one embodiment, a packet switching device creates multiple virtual packet switching devices within the same physical packet switching device using virtual machines and sharing particular physical resources of the packet switching device. One embodiment uses this functionality to change the operating version (e.g., upgrade or downgrade) of the packet switching device by originally operating according to a first operating version, operating according to both a first and second operating version, and then ceasing operating according to the first operating version. Using such a technique, a packet switching device can be upgraded or downgraded while fully operating (e.g., without having to reboot line cards and route processing engines).

Abstract: Described herein are methods and systems for automatically generating routing configuration files based on a network topology and a collection of routing configuration templates. Such automatically generated routing configuration files may be suitable for a network running one or more of the RIP, EIGRP, OSPF, IS-IS and BGP routing protocols. The network topology may be specified in a graph description language, such as DOT, and/or a graph modeling language, such as GraphML. The routing configuration templates include certain routing protocol commands or sequence of commands that are frequently repeated in the configuration of a network device. Based on the network topology, the routing configuration templates are instantiated in a certain fashion, and any placeholders therein are replaced with information specific to the network topology.

Abstract: In one embodiment, a network device may detect a data plane critical fault condition, while a corresponding control plane is not experiencing a critical fault condition. In response to a network device based critical fault condition, the network device may activate and advertise an increased and expensive usable metric for each network interface of the network device. On the other hand, in response to an interface based critical fault condition, the network device may activate and advertise an increased and expensive usable metric for one or more particular network interfaces of the interface based critical fault, and signals, over the control plane to a corresponding network device at an opposing end of each particular network interface of the interface based critical fault, a request to activate and advertise an increased and expensive usable metric at the opposing end of each particular network interface.

Abstract: In one embodiment, a packet switching device creates multiple virtual packet switching devices within the same physical packet switching device using virtual machines and sharing particular physical resources of the packet switching device. One embodiment uses this functionality to change the operating version (e.g., upgrade or downgrade) of the packet switching device by originally operating according to a first operating version, operating according to both a first and second operating version, and then ceasing operating according to the first operating version. Using such a technique, a packet switching device can be upgraded or downgraded while fully operating (e.g., without having to reboot line cards and route processing engines).

Abstract: In one embodiment, a packet switching device creates multiple virtual packet switching devices within the same physical packet switching device using virtual machines and sharing particular physical resources of the packet switching device. One embodiment uses this functionality to change the operating version (e.g., upgrade or downgrade) of the packet switching device by originally operating according to a first operating version, operating according to both a first and second operating version, and then ceasing operating according to the first operating version. Using such a technique, a packet switching device can be upgraded or downgraded while fully operating (e.g., without having to reboot line cards and route processing engines).

Abstract: In one embodiment, an autonomous system (AS) policy-adaptive confederation selectively manipulates the ordered list of traversed AS's using AS's of members of the policy-adaptive confederation and/or the AS of the policy-adaptive confederation itself when advertising to routers of AS's outside the policy-adaptive confederation. In one embodiment, a first member router of a first autonomous system (AS) within a policy-adaptive confederation identified by a confederation AS receives from a second member router of a second AS within the policy-adaptive confederation a route advertisement for a first route associated with a first ordered AS list identifying one or more AS's within the policy-adaptive confederation. The first member advertises the first route associated with the first ordered AS list not including the confederation AS to a first external router external to the policy-adaptive confederation.

Abstract: Hiding a service node in a network from a network topology is provided. In one embodiment, for example, an apparatus for hiding a service node in a network from a network topology, the apparatus comprising: a network interface; a processor; and one or more stored sequences of instructions which, when executed by the processor, cause the processor to perform: discovering a service node in a data network in accordance with a link-state protocol wherein the service node provides a network topology dependent service other than packet forwarding; establishing a link-state adjacency with the service node and one or more packet forwarding nodes in accordance with the link-state protocol; receiving a link-state advertisement; in response to identifying the link-state advertisement as an originating link-state advertisement sent from the service node, suppressing flooding of the received link-state advertisement to the one or more packet forwarding nodes.

Abstract: In one embodiment, a packet switching device determines backup forwarding paths based on route distinguisher correlation values. A route distinguisher correlation value is some value associated with multiple routes, which allows a packet switching device to consider routes associated with a same route distinguisher correlation value, but having different route distinguishers and a same prefix to be considered as going to a same destination. Examples of route distinguisher correlation value used in one embodiment include, but are not limited to: scalar values, a route distinguisher of a different route, a virtual private network associated with a different route; a route target associated with the a different route; or a Border Gateway Protocol (BGP) Next-hop address associated with a different route.

Abstract: In one embodiment, a packet switching device assigns a same particular packet switching label to each particular route of a plurality of particular routes having the same one or more best paths, wherein the plurality of particular routes includes routes from at least two different forwarding groups. A forwarding group is defined as a specific route, one or more routes associated with a same customer edge router, or one or more routes associated with a single virtual routing and forwarding domain (VRF). The packet switching device advertises to other packet switching device(s) to add this same particular label to packets having one of the plurality of particular routes, which they do. The packet switching device then packet switches packets based on the particular label received in a label field in a header of these packets.

Abstract: In one embodiment, an operating system kernel and/or one or more processes of a high-availability system are modified while the system is operating and providing high-availability service. In accomplishing this, one embodiment uses a second virtual machine to operate a second operating system kernel including a second set of processes in the standby mode, which receive state information from corresponding process(es) in the active mode. Individually, the operating system kernel and processes within the second set of processes may be a same or different version of their counterpart in a first virtual machine and its processes which are being replaced. When the second set of processes have acquired sufficient state information to perform the standby role, the operation of the first virtual machine is typically ceased as the version modified second virtual machine is performing the version modified functionality of the first virtual machine.

Abstract: In one embodiment, an access component of a local network edge device receives traffic, and generates a frame for the traffic that includes a remote context label that identifies an access component of the remote network edge device to which the traffic is to be forwarded upon arrival at the remote network edge device, and a virtual circuit label corresponding to a particular virtual service of the traffic. The local network edge device forwards the frame towards the remote network edge device. In another embodiment, the frame may be received at a core component of the remote network edge device, an in response to the remote context label identifying an access component of the remote network edge device, forwarded to the access component, which determines the particular virtual service, and forwards the traffic from the frame out the access component towards an endpoint for the traffic.

Abstract: Described herein are methods and systems for automatically generating routing configuration files based on a network topology and a collection of routing configuration templates. Such automatically generated routing configuration files may be suitable for a network running one or more of the RIP, EIGRP, OSPF, IS-IS and BGP routing protocols. The network topology may be specified in a graph description language, such as DOT, and/or a graph modeling language, such as GraphML. The routing configuration templates include certain routing protocol commands or sequence of commands that are frequently repeated in the configuration of a network device. Based on the network topology, the routing configuration templates are instantiated in a certain fashion, and any placeholders therein are replaced with information specific to the network topology.

Abstract: In one embodiment, an access component of a local network edge device receives traffic, and generates a frame for the traffic that includes a remote context label that identifies an access component of the remote network edge device to which the traffic is to be forwarded upon arrival at the remote network edge device, and a virtual circuit label corresponding to a particular virtual service of the traffic. The local network edge device forwards the frame towards the remote network edge device. In another embodiment, the frame may be received at a core component of the remote network edge device, an in response to the remote context label identifying an access component of the remote network edge device, forwarded to the access component, which determines the particular virtual service, and forwards the traffic from the frame out the access component towards an endpoint for the traffic.

Abstract: In one embodiment, an edge device of a core network may receive a plurality of packets from a peripheral network having a plurality of active connections to the core network, where each packet has a destination address and a source address. The edge device may compute a hash on the destination address or the source address of each packet, and determine whether the computed hash corresponds to the edge device. In response to the computed hash not corresponding to the edge device, the edge device may drop the packet, and in response to the computed hash corresponding to the edge device, the edge device may process the packet to forward the packet, where the dropping and processing load balances the plurality of packets over the active connections and prevents formation of loops in the core network.

Abstract: In one embodiment, a list of border node next hop options is maintained in a memory. The list of border node next hop options includes one or more of border nodes that may be utilized to reach one or more prefixes. An index value is associated with each border node of the list of border node next hop options. A list of labels is also maintained in the memory. The index value of each border node is associated with a corresponding label for a path to reach that border node. When a change to the one or more border nodes is detected, the list of border node next hop options is updated to remove a border node. However, a label for the path to reach the border node is maintained in the list of labels for at least a period of time.

Abstract: In one embodiment, a packet switching device is configured to perform a lookup operation, based on a particular per-CE label (per-Customer Edge label) included in a particular packet, in a forwarding data structure for identifying forwarding information for the particular packet. When a corresponding outbound path is unavailable, a per-VRF (per-Virtual Routing and Forwarding) lookup operation in a VRF data structure, identified based on the particular per-CE label, based on a destination address of a packet encapsulated within the received packet. A corresponding packet is forwarded based on the results of the VRF lookup operation. In one embodiment, a set of more than one egress line card is identified based on this lookup operation, and packets of different routes are load balanced among egress line cards in this identified set of egress line cards.

Abstract: In one embodiment, a network device may detect a data plane critical fault condition, while a corresponding control plane is not experiencing a critical fault condition. In response to a network device based critical fault condition, the network device may activate and advertise an increased and expensive usable metric for each network interface of the network device. On the other hand, in response to an interface based critical fault condition, the network device may activate and advertise an increased and expensive usable metric for one or more particular network interfaces of the interface based critical fault, and signals, over the control plane to a corresponding network device at an opposing end of each particular network interface of the interface based critical fault, a request to activate and advertise an increased and expensive usable metric at the opposing end of each particular network interface.

Abstract: In one embodiment, a network device may detect a data plane critical fault condition, while a corresponding control plane is not experiencing a critical fault condition. In response to a network device based critical fault condition, the network device may activate and advertise an increased and expensive usable metric for each network interface of the network device. On the other hand, in response to an interface based critical fault condition, the network device may activate and advertise an increased and expensive usable metric for one or more particular network interfaces of the interface based critical fault, and signals, over the control plane to a corresponding network device at an opposing end of each particular network interface of the interface based critical fault, a request to activate and advertise an increased and expensive usable metric at the opposing end of each particular network interface.

Abstract: In one embodiment, a packet switching device is configured to perform a lookup operation, based on a particular per-CE label (per-Customer Edge label) included in a particular packet, in a forwarding data structure for identifying forwarding information for the particular packet. When a corresponding outbound path is unavailable, a per-VRF (per-Virtual Routing and Forwarding) lookup operation in a VRF data structure, identified based on the particular per-CE label, based on a destination address of a packet encapsulated within the received packet. A corresponding packet is forwarded based on the results of the VRF lookup operation. In one embodiment, a set of more than one egress line card is identified based on this lookup operation, and packets of different routes are load balanced among egress line cards in this identified set of egress line cards.