Abstract: A method is performed at a source node in a network of nodes configured with a link state protocol, and in which at least some of the nodes are enabled for multiprotocol label switching (MPLS). The node discovers and stores a link state topology representing the nodes of the network, links between the nodes, path-costs for the links, and whether each link is enabled or not enabled for MPLS. The node determines one or more shortest paths from the source node to a destination node among the nodes based on traversing the link state topology and, while the node traverses the link state topology, detects whether each shortest path supports or does not support MPLS end-to-end dataplane continuity. The node programs an IP dataplane with each shortest path, and programs an MPLS dataplane with ones of the one or more shortest paths that support the end-to-end MPLS continuity.

Abstract: Various systems and methods for using strict path forwarding. For example, one method involves receiving an advertisement at a node. The advertisement includes a segment identifier (SID). In response to receiving the advertisement, the node determines whether the SID is a strict SID or not. If the SID is a strict SID, the node generates information, such as forwarding information that indicates how to forward packets along a strict shortest path corresponding to the strict SID.

Abstract: A method is performed at a source node in a network of nodes configured with a link state protocol, and in which at least some of the nodes are enabled for multiprotocol label switching (MPLS). The node discovers and stores a link state topology representing the nodes of the network, links between the nodes, path-costs for the links, and whether each link is enabled or not enabled for MPLS. The node determines one or more shortest paths from the source node to a destination node among the nodes based on traversing the link state topology and, while the node traverses the link state topology, detects whether each shortest path supports or does not support MPLS end-to-end dataplane continuity. The node programs an IP dataplane with each shortest path, and programs an MPLS dataplane with ones of the one or more shortest paths that support the end-to-end MPLS continuity.

Abstract: Various systems and methods for using strict path forwarding. For example, one method involves receiving an advertisement at a node. The advertisement includes a segment identifier (SID). In response to receiving the advertisement, the node determines whether the SID is a strict SID or not. If the SID is a strict SID, the node generates information, such as forwarding information, that indicates how to forward packets along a strict shortest path corresponding to the strict SID.

Abstract: Various systems and methods for bypassing one or more non-capable nodes. For example, one method involves a capable node determining that an adjacent node is non-capable, where capable nodes are configured to implement a data plane capability and non-capable nodes are not. The method then involves identifying a downstream node that is capable. The downstream node is on a shortest path. The method also involves generating information that identifies a tunnel to the downstream node.

Abstract: Various implementations disclosed herein enable malleable routing for data packets. For example, in various implementations, a method of routing a type of data packets is performed by a device. In some implementations, the device includes a non-transitory memory and one or more processors coupled with the non-transitory memory. In some implementations, the method includes determining a routing criterion to transmit a set of data packets across a network. In some implementations, the method includes identifying network nodes and communication links in the network that satisfy the routing criterion. In some implementations, the method includes determining a route for the set of data packets through the network nodes and the communication links that satisfy the routing criterion. In some implementations, the method includes configuring the network nodes that are on the route with configuration information that allows the set of data packets to propagate along the route.

Abstract: Various systems and methods for bypassing one or more non-capable nodes. For example, one method involves a capable node determining that an adjacent node is non-capable, where capable nodes are configured to implement a data plane capability and non-capable nodes are not. The method then involves identifying a downstream node that is capable. The downstream node is on a shortest path. The method also involves generating information that identifies a tunnel to the downstream node.

Abstract: Various systems and methods for bypassing one or more non-capable nodes. For example, one method involves a capable node determining that an adjacent node is non-capable, where capable nodes are configured to implement a data plane capability and non-capable nodes are not. The method then involves identifying a downstream node that is capable. The downstream node is on a shortest path. The method also involves generating information that identifies a tunnel to the downstream node.

Abstract: A method and system are disclosed for distributing (advertising) segment identifiers in network functions virtualization and/or software defined networking environments. An exemplary method includes receiving a route advertisement that includes a prefix with a forwarding address for a first network element and receiving a segment identifier (SID) advertisement that includes a prefix SID for the prefix. The route advertisement may be received from a second network element proxying control plane functions for the first network element. Reachability information for the first network element is updated based on the route advertisement and the SID advertisement.

Abstract: Methods and systems are disclosed for detection of reroute occurrences in segment routing enabled networks. In one embodiment, a method includes receiving, at a first node in a communications network, a test message comprising a header, where the header comprises one or more segment identifiers. This embodiment of the method further includes detecting a first indicator of a rerouted test path for the message and sending an outgoing message to a node determined using the header, where sending the outgoing message comprises including in the outgoing message a second indicator that the test message has been rerouted. An embodiment of a system includes a network interface adapted for data communication with one or more nodes of a communications network and a processor operably coupled to the network interface and adapted to implement an embodiment of the method.

Abstract: Various systems and methods for bypassing one or more non-capable nodes. For example, one method involves a capable node determining that an adjacent node is non-capable, where capable nodes are configured to implement a data plane capability and non-capable nodes are not. The method then involves identifying a downstream node that is capable. The downstream node is on a shortest path. The method also involves generating information that identifies a tunnel to the downstream node.

Abstract: Various systems and methods for using strict path forwarding. For example, one method involves receiving an advertisement at a node. The advertisement includes a segment identifier (SID). In response to receiving the advertisement, the node determines whether the SID is a strict SID or not. If the SID is a strict SID, the node generates information, such as forwarding information, that indicates how to forward packets along a strict shortest path corresponding to the strict SID.

Abstract: A method and system are disclosed for distributing (advertising) segment identifiers in network functions virtualization and/or software defined networking environments. An exemplary method includes receiving a route advertisement that includes a prefix with a forwarding address for a first network element and receiving a segment identifier (SID) advertisement that includes a prefix SID for the prefix. The route advertisement may be received from a second network element proxying control plane functions for the first network element. Reachability information for the first network element is updated based on the route advertisement and the SID advertisement.

Abstract: Various systems and methods for bypassing one or more non-capable nodes. For example, one method involves a capable node determining that an adjacent node is non-capable, where capable nodes are configured to implement a data plane capability and non-capable nodes are not. The method then involves identifying a downstream node that is capable. The downstream node is on a shortest path. The method also involves generating information that identifies a tunnel to the downstream node.

Abstract: An apparatus and method for resolving services to nodal segments. The method involves receiving an advertisement. The advertisement includes a service address associated with a service. The method further involves identifying an originator node for the service, where the originator node is associated with a nodal segment identifier. The method further involves updating the advertisement. Updating the advertisement involves adding information identifying the originator node to the advertisement.

Abstract: An apparatus and method for resolving services to nodal segments. The method involves receiving an advertisement. The advertisement includes a service address associated with a service. The method further involves identifying an originator node for the service, where the originator node is associated with a nodal segment identifier. The method further involves updating the advertisement. Updating the advertisement involves adding information identifying the originator node to the advertisement.

Abstract: A novel technique is provided for preventing routing loops by disseminating Border Gateway Protocol (BGP) attribute information in an Open Shortest Path First (OSPF) configured network. Specifically, a new OSPF sub-type-length-value (TLV) is introduced for transporting a conventional BGP autonomous system (AS) path attribute through the OSPF-configured network. Like the BGP AS-path attribute, the new OSPF AS-path sub-TLV is configured to store a set of AS numbers corresponding to the AS path of one or more advertised routes. Thus, when a network device receives an OSPF link-state advertisement (LSA) containing the novel AS-path sub-TLV, the network device determines whether it resides in an autonomous system whose AS number is stored in the sub-TLV. If so, the network device does not install the LSA's advertised routes in its link-state database since the routes, if installed, could result in routing loops.

Abstract: A technique maintains Interior Gateway Protocol (IGP) transparency of Virtual Private Network (VPN) routes when Border Gateway Protocol (BGP) is used as a Provider Edge Device (PE) to Customer Edge Device (CE) protocol in a computer network. According to the novel technique, a first CE generates a BGP advertisement to advertise one or more VPN routes of its customer network, the BGP advertisement having one or more transitive IGP attributes for the advertised routes. The first CE sends the BGP advertisement to a first PE, which then propagates the BGP advertisement among devices of a provider network maintaining the transitive IGP attributes. A second PE sends the BGP advertisement to a second CE, along with the transitive IGP attributes. Upon receiving the BGP advertisement, the second CE converts the BGP advertisement and transitive IGP attributes into corresponding IGP advertisements.

Abstract: A technique gracefully shuts down network resources, such as nodes, interfaces and protocols, in a data network in a manner that minimizes network disruption. The technique may be used with both connectionless and connection-oriented networking systems. A node gracefully shuts down a network resource associated with the node by i) notifying other nodes in the network that the resource is being gracefully shutdown, ii) waiting for a condition to occur, and iii) when the condition occurs, shutting down the resource. The condition may include the expiration of a predetermined amount of time and/or monitoring the resource to determine if the resource has reached a certain level of activity. In response to receiving a notification that a resource is being gracefully shutdown, a node takes action to reroute traffic around the resource. If no alternative route is available, the node may continue to route traffic to the resource until it is shut down.

Abstract: A technique maintains Interior Gateway Protocol (IGP) transparency of Virtual Private Network (VPN) routes when Border Gateway Protocol (BGP) is used as a Provider Edge Device (PE) to Customer Edge Device (CE) protocol in a computer network. According to the novel technique, a first CE generates a BGP advertisement to advertise one or more VPN routes of its customer network, the BGP advertisement having one or more transitive IGP attributes for the advertised routes. The first CE sends the BGP advertisement to a first PE, which then propagates the BGP advertisement among devices of a provider network maintaining the transitive IGP attributes. A second PE sends the BGP advertisement to a second CE, along with the transitive IGP attributes. Upon receiving the BGP advertisement, the second CE converts the BGP advertisement and transitive IGP attributes into corresponding IGP advertisements.