Abstract: A method and apparatus for enabling dynamic reroute in a redundant system is provided. A network device is operative to determine whether a state of a link that couples the first network device with a third network device is active. In response to determining that the state of the link is active causing a payload of a packet to be forwarded towards the third network device through the second network interface of the first network device based on a second IP address; and responsive to determining that the state of the link is not active causing the second payload to be forwarded towards the third network device through a third network interface of the second network device based on the second IP address.

Abstract: Methods and apparatuses for fast convergence in Layer 2 overlay network are described. Forwarding of Layer 2 (L2) traffic addressed to one or more remote L2 destinations is performed according to a remote L2 (RL2) instance, where the RL2 instance identifies a primary path for forwarding the traffic towards the remote L2 destinations, and a provider edge service label (PESL) instance associated with a broadcast domain including one or more network devices for forwarding the L2 traffic towards the L2 destination, and where the PESL instance is identified with a unique immutable PESL instance label. In response to a network event, an update of the RL2 instance is performed. The update results in an update of a data plane for forwarding the L2 traffic without necessitating an update of forwarding table entries for each one of the one or more remote L2 destination.

Abstract: Methods and apparatuses for fast convergence in Layer 2 overlay network are described. Forwarding of Layer 2 (L2) traffic addressed to one or more remote L2 destinations is performed according to a remote L2 (RL2) instance, where the RL2 instance identifies a primary path for forwarding the traffic towards the remote L2 destinations, and a provider edge service label (PESL) instance associated with a broadcast domain including one or more network devices for forwarding the L2 traffic towards the L2 destination, and where the PESL instance is identified with a unique immutable PESL instance label. In response to a network event, an update of the RL2 instance is performed. The update results in an update of a data plane for forwarding the L2 traffic without necessitating an update of forwarding table entries for each one of the one or more remote L2 destination.

Abstract: A method and apparatus for enabling dynamic reroute in a redundant system is provided. A network device is operative to determine whether a state of a link that couples the first network device with a third network device is active. In response to determining that the state of the link is active causing a payload of a packet to be forwarded towards the third network device through the second network interface of the first network device based on a second IP address; and responsive to determining that the state of the link is not active causing the second payload to be forwarded towards the third network device through a third network interface of the second network device based on the second IP address.

Abstract: A network device, is to be deployed in a network between a first network domain and a second network domain, and is to be configured for fast reroute. The network device includes a first traffic forwarder control module, corresponding to the first network domain, which is to determine a primary next hop in the first network domain. The control plane includes a second traffic forwarder control module, corresponding to the second network domain, which is to determine a backup next hop in the second network domain. The backup next hop is to be used as a fast reroute for the primary next hop in response to a failure associated with the primary next hop. The control plane includes a controller module, in communication with the first and second traffic forwarder control modules, which is to configure a forwarding structure of the forwarding plane with the primary and backup next hops.

Abstract: Exemplary methods performed by a first network device (ND) include generating first and second prefix entries associating incoming Internet Protocol (IP) traffic to first and second data structures (DSs), respectively. Generating the first DS includes generating a first proxy including forwarding information causing incoming IP traffic to be forwarded to a second ND, and generating a second proxy referencing a third DS. Generating the second DS includes generating a first proxy including forwarding information causing incoming IP traffic to be forwarded to the second ND, and generating a second proxy referencing the third DS. The methods include generating the third DS including forwarding information causing the incoming IP traffic to be forwarded to a third ND, the third DS further including first state information indicating whether the forwarding information included in the first proxies of the first and second DSs should be used for forwarding the incoming IP traffic.

Abstract: Exemplary methods include generating a first fast reroute (FRR) next hop (NH) comprising of a first primary next hop (PNH), a first secondary next hop (SNH), and a first attribute, wherein the first PNH and first SNH include forwarding information that causes traffic to be forwarded towards a second and third network device, respectively. The methods include sending a first request to a forwarding plane to generate a second FRR NH comprising of a second PNH, a second SNH, and a second attribute. The methods include updating contents of the first FRR NH, and sending a second request to the forwarding plane to update the second FRR NH, wherein the second request causes the forwarding plane to determine whether to revert back to using the second PNH based on whether the first attribute included in the second request is different from the second attribute of the second FRR NH.

Abstract: A method is disclosed that is implemented by a router for executing an internet protocol fast reroute process in response to a network event invalidating a current route to a destination node without degrading forwarding plane functionality or performance caused by indirect forwarding information base lookups. The method comprises a set steps including receiving or generating the network event by the router, the network event associated with a network event identifier and looking up the network event identifier in an event table to determine routes that are affected by the network event. The method further includes determining whether a route with a fast reroute forwarding object is affected by the network event in the routing information base and overwriting a current next hop forwarding object using a backup next hop forwarding object in the forwarding information base.

Abstract: Exemplary methods include generating a first fast reroute (FRR) next hop (NH) comprising of a first primary next hop (PNH), a first secondary next hop (SNH), and a first attribute, wherein the first PNH and first SNH include forwarding information that causes traffic to be forwarded towards a second and third network device, respectively. The methods include sending a first request to a forwarding plane to generate a second FRR NH comprising of a second PNH, a second SNH, and a second attribute. The methods include updating contents of the first FRR NH, and sending a second request to the forwarding plane to update the second FRR NH, wherein the second request causes the forwarding plane to determine whether to revert back to using the second PNH based on whether the first attribute included in the second request is different from the second attribute of the second FRR NH.

Abstract: Exemplary methods performed by a first network device (ND) include generating first and second prefix entries associating incoming Internet Protocol (IP) traffic to first and second data structures (DSs), respectively. Generating the first DS includes generating a first proxy including forwarding information causing incoming IP traffic to be forwarded to a second ND, and generating a second proxy referencing a third DS. Generating the second DS includes generating a first proxy including forwarding information causing incoming IP traffic to be forwarded to the second ND, and generating a second proxy referencing the third DS. The methods include generating the third DS including forwarding information causing the incoming IP traffic to be forwarded to a third ND, the third DS further including first state information indicating whether the forwarding information included in the first proxies of the first and second DSs should be used for forwarding the incoming IP traffic.

Abstract: A network device, is to be deployed in a network between a first network domain and a second network domain, and is to be configured for fast reroute. The network device includes a first traffic forwarder control module, corresponding to the first network domain, which is to determine a primary next hop in the first network domain. The control plane includes a second traffic forwarder control module, corresponding to the second network domain, which is to determine a backup next hop in the second network domain. The backup next hop is to be used as a fast reroute for the primary next hop in response to a failure associated with the primary next hop. The control plane includes a controller module, in communication with the first and second traffic forwarder control modules, which is to configure a forwarding structure of the forwarding plane with the primary and backup next hops.

Abstract: A network device, is to be deployed in a network between a first network domain and a second network domain, and is to be configured for fast reroute. The network device includes a first traffic forwarder control module, corresponding to the first network domain, which is to determine a primary next hop in the first network domain. The control plane includes a second traffic forwarder control module, corresponding to the second network domain, which is to determine a backup next hop in the second network domain. The backup next hop is to be used as a fast reroute for the primary next hop in response to a failure associated with the primary next hop. The control plane includes a controller module, in communication with the first and second traffic forwarder control modules, which is to configure a forwarding structure of the forwarding plane with the primary and backup next hops.

Abstract: A method is implemented by a network element to improve efficiency of loop free alternative (LFA) path computation by caching data from a shortest path first calculation for use in the LFA path calculation. The shortest path first calculation determines a shortest path from a source vertex to each vertex in a network topology graph representing the network in which the network element operates, where an endpoint for each shortest path is the shortest path vertex, and where each shortest path determined by the shortest path first calculation is stored.

Abstract: A method is implemented by a network element to improve efficiency of loop free alternative (LFA) path computation by caching data from a shortest path first calculation for use in the LFA path calculation. The shortest path first calculation determines a shortest path from a source vertex to each vertex in a network topology graph representing the network in which the network element operates, where an endpoint for each shortest path is the shortest path vertex, and where each shortest path determined by the shortest path first calculation is stored.

Abstract: A method is implemented by a network element for determining a next hop of a backup path for a fast reroute process to be utilized in response to a network event invalidating a primary path to a destination node. The method reduces computational requirements of the network element by reducing a number of paths to be evaluated without affecting selection of the backup path. The method selects a neighbor node P of a source node S to calculate a shortest path tree (SPT) for P for use in identifying backup paths for S. The SPT is calculated for P, pruning paths from the SPT that traverse S or that fail an LFA condition. P is selected for the next hop of the backup path for a destination node X where the SPT of P provides an LFA path from S to the destination node X.

Abstract: An hierarchical LSP is established to transport packets belonging to a FEC attached to an egress LSR and includes an egress LSR LSP that is common for each of the FECs attached to the egress LSR and forms a path from the ingress LSR through intermediate LSR(s) to the egress LSR. The egress LSR LSP is used when label switching packets destined for the FECs attached to the egress LSR. The hierarchical LSP also includes a unique FEC LSP for each FEC that is used by the egress LSR to identify and forward packets to that FEC. Responsive to a topology change that changes a next-hop of the ingress LSR to reach the egress LSR, the ingress LSR modifies an entry in a forwarding structure to change the next-hop for the egress LSR LSP and does not modify substantially any forwarding structure entities for the FEC LSPs.

Abstract: A method is disclosed that is implemented by a router for executing an internet protocol fast reroute process in response to a network event invalidating a current route to a destination node without degrading forwarding plane functionality or performance caused by indirect forwarding information base lookups. The method comprises a set steps including receiving or generating the network event by the router, the network event associated with a network event identifier and looking up the network event identifier in an event table to determine routes that are affected by the network event. The method further includes determining whether a route with a fast reroute forwarding object is affected by the network event in the routing information base and overwriting a current next hop forwarding object using a backup next hop forwarding object in the forwarding information base.

Abstract: Signaling a Label Switched Path (LSP) tunneling model is described. In one embodiment, a network element that is acting as an egress network element in a Multiprotocol Label Switching (MPLS) network signals multiple LSPs for multiple disparate applications provided in the MPLS network that each require a different type of tunneling model. The network element transmits a first label mapping message for one of the LSPs that includes an indication of a first tunneling model type applicable for that LSP. That LSP is to be used to transport traffic in the MPLS network for a first one of the disparate applications that requires the indicated first tunneling model type. The network element further transits a second label mapping message for a second one of the LSPs that includes an indication of a second tunneling model type applicable for that LSP. That LSP is to be used to transport traffic in the MPLS network for a second one of the disparate applications that requires the indicated second tunneling model type.

Abstract: A method for improving LDP (Label Distribution Protocol) convergence time in an MPLS (Multi-Protocol Label Switching) network is described. An hierarchical LSP is established to transport packets belonging to a FEC attached to an egress LSR. The hierarchical LSP includes an egress LSR LSP that is common for each of the FECs attached to the egress LSR and forms a path from the ingress LSR through one or more intermediate LSRs to the egress LSR. The egress LSR LSP is used when label switching packets destined for the FECs attached to the egress LSR. The hierarchical LSP also includes a unique FEC LSP for each FEC that is used by the egress LSR to identify and forward packets to that FEC. Responsive to a topology change that changes a next-hop of the ingress LSR to reach the egress LSR, the ingress LSR modifies an entry in a forwarding structure to change the next-hop for the egress LSR LSP and does not modify substantially any forwarding structure entities for the FEC LSPs.