Abstract: A router node may be configured for communication of multicast traffic in a network fabric which may include a plurality of spine nodes interconnected to a plurality of leaf nodes. The router node may be configured as one of the leaf nodes and serve as a first hop router for multicast traffic. At the router node, a message for flooding the network fabric may be sent based on an indication of communication of multicast traffic for a multicast group from a source device. The message may include at least one spine node identifier of at least one preferred spine node joined to the multicast group at the router node. The message may be for indicating, to at least one of the leaf nodes, to prioritize joining to the multicast group at the at least one preferred spine node according to at least one spine node identifier.

Abstract: A router node may be configured for communication of multicast traffic in a network fabric which may include a plurality of spine nodes interconnected to a plurality of leaf nodes. The router node may be configured as one of the leaf nodes and serve as a first hop router for multicast traffic. At the router node, a message for flooding the network fabric may be sent based on an indication of communication of multicast traffic for a multicast group from a source device. The message may include at least one spine node identifier of at least one preferred spine node joined to the multicast group at the router node. The message may be for indicating, to at least one of the leaf nodes, to prioritize joining to the multicast group at the at least one preferred spine node according to at least one spine node identifier.

Abstract: In one embodiment, a first computer networking device executes an election algorithm to determine whether at least the first computer networking device or a second computer networking device is responsible for forwarding, to at least one receiving device, communications addressed to a specified group of computing devices. The first computer networking device may further store first data indicating that the first computer networking device is responsible for forwarding the communications. However, in response to the first computer networking device determining that it is no longer receiving the communications, it may store second data indicating that the first computer networking device is no longer responsible for forwarding the communications and may send, to the second computer networking device, third data indicating that the first computer networking device is not receiving the communications.

Abstract: In one embodiment, a first label-distribution-protocol (LDP) session is established between a first interface of a first computing device and a second computing device, while a second LDP session is established between a second interface and the second computing device. The method may further comprise receiving a request from a third computing device to subscribe to a multicast group, storing an association between a first label, the multicast group, and the first interface, and sending, to the second computing device via the first LDP session, an indication that the first label is associated with the multicast group. Further, the method may include receiving a request from a fourth computing device to subscribe to the multicast group, storing an association between a second label, the multicast group and, the second interface, and sending, via the second LDP session, an indication that the second label is associated with the multicast group.

Abstract: A first network device joins a redundancy group of a multihomed network element that is connected to a computing device. The first network device detects an active link between the first network device and the computing device, and receives from the computing device, a subscription to a multicast flow. The first network device adds the subscription to a first list of active multicast subscriptions stored on the first network device. The first network device sends a unicast notification to a second network device of the multihomed network element. The unicast notification causes the subscription to be added to a second list of active multicast subscriptions stored on the second network device.

Abstract: Seamless multipoint label distribution protocol (mLDP) transport over a bit index explicit replication (BIER) core may be provided. First, it may be determined that a first plurality of network devices comprise BIER edge routers. Then, in response to determining that the first plurality of network devices comprise BIER edge routers, a Targeted Label Distribution Protocol (T-LDP) session may be created between a first one of the first plurality of network devices and a second one of the first plurality of network devices. Next, an address of a peer device connected to the second one of the first plurality of network devices may be advertised by the second one of the first plurality of network devices over the T-LDP session.

Abstract: In one illustrative example, a network node connected in a network fabric may identify that it is established as part of a multicast distribution tree for forwarding multicast traffic from a source node to one or more host receiver devices of a multicast group. In response, the network node may propagate in the network fabric a message for advertising the network node as a candidate local source node at which to join the multicast group. The message for advertising may include data such as a reachability metric. The propagation of the message may be part of a flooding of such messages in the network fabric. The network node serving as the candidate local source node may thereafter “locally” join a host receiver device in the multicast group at the network node so that the device may receive the multicast traffic from the source node via the network node.

Abstract: A router node may be configured for communication of multicast traffic in a network fabric which may include a plurality of spine nodes interconnected to a plurality of leaf nodes. The router node may be configured as one of the leaf nodes and serve as a first hop router for multicast traffic. At the router node, a message for flooding the network fabric may be sent based on an indication of communication of multicast traffic for a multicast group from a source device. The message may include at least one spine node identifier of at least one preferred spine node joined to the multicast group at the router node. The message may be for indicating, to at least one of the leaf nodes, to prioritize joining to the multicast group at the at least one preferred spine node according to at least one spine node identifier.

Abstract: Systems, methods, and computer-readable media for controlling multicast traffic flows through provider edge routers. In some examples, a multicast traffic of one or more multicast traffic flows is received from a multicast source at a first provider edge router of a plurality of provider edge routers. A multicast routing message including a loopback address of the first provider edge router can be originated at the first provider edge router. The multicast routing message can be flooded into a multicast core network for controlling traffic in the one or more multicast flows through the multicast core network to the first provider edge router. Subsequently, multicast joins can be received at the first provider edge router for establishing the one or more multicast flows through the multicast core network based on the multicast routing message including the loopback address of the first provider edge router.

Abstract: Multicast error detection and recovery may be provided. A join request for a multicast stream may be sent from a first network node to a second network node. The join request may be sent over a first link of a plurality of links between the first network node and the second network node. A redirect message indicating that the second network node cannot accommodate the join request may be received by the first network node from the second network node. In response to receiving the redirect message, the join request for the multicast stream may not be sent on a second link of the plurality of links by the first network node to the second network node. And in response to receiving the redirect message, an alternate upstream network node may be determined by the first network node to send the join request for the multicast stream to.

Abstract: In one illustrative example, a network node connected in a network fabric may identify that it is established as part of a multicast distribution tree for forwarding multicast traffic from a source node to one or more host receiver devices of a multicast group. In response, the network node may propagate in the network fabric a message for advertising the network node as a candidate local source node at which to join the multicast group. The message for advertising may include data such as a reachability metric. The propagation of the message may be part of a flooding of such messages in the network fabric. The network node serving as the candidate local source node may thereafter “locally” join a host receiver device in the multicast group at the network node so that the device may receive the multicast traffic from the source node via the network node.

Abstract: Multicast error detection and recovery may be provided. A join request for a multicast stream may be sent from a first network node to a second network node. The join request may be sent over a first link of a plurality of links between the first network node and the second network node. A redirect message indicating that the second network node cannot accommodate the join request may be received by the first network node from the second network node. In response to receiving the redirect message, the join request for the multicast stream may not be sent on a second link of the plurality of links by the first network node to the second network node. And in response to receiving the redirect message, an alternate upstream network node may be determined by the first network node to send the join request for the multicast stream to.

Abstract: In one embodiment, a method includes receiving, by a first router, data from a network component. The method also includes determining, by the first router, a first link bandwidth capacity between the first router and a host device and determining, by the first router, a first score for the first router based on the first link bandwidth capacity. The method also includes determining, by the first router, a second link bandwidth capacity between a second router and the host device and determining, by the first router, a second score for the second router based on the second link bandwidth capacity. The method further includes comparing, by the first router, at least the first score and the second score to determine a highest score and assigning, by the first router, an edge router associated with the highest score to communicate the data to the host device.

Abstract: In one illustrative example, a multicast traceroute facility for a plurality of interconnected router nodes which are configured to communicate IP multicast traffic amongst hosts is described. The multicast traceroute facility may be for use in processing a multicast traceroute batch query packet which indicates a batch of multicast traceroute queries of a batch query, for identifying a plurality of traced paths for a batch of IP multicast traffic flows. Each identified traced path may be associated with one or more links, each of which has a link metric that satisfies a requested link metric (e.g. a link bandwidth). Resources for satisfying the requested link metric may be reserved for a predetermined or specified time period. The batch of IP multicast traffic flows may be established via at least some of the interconnected router nodes according to the plurality of traced paths identified from the query packet processing.

Abstract: Seamless multipoint label distribution protocol (mLDP) transport over a bit index explicit replication (BIER) core may be provided. First, it may be determined that a first plurality of network devices comprise BIER edge routers. Then, in response to determining that the first plurality of network devices comprise BIER edge routers, a Targeted Label Distribution Protocol (T-LDP) session may be created between a first one of the first plurality of network devices and a second one of the first plurality of network devices. Next, an address of a peer device connected to the second one of the first plurality of network devices may be advertised by the second one of the first plurality of network devices over the T-LDP session.

Abstract: Systems, methods, and computer-readable media for controlling multicast traffic flows through provider edge routers. In some examples, a multicast traffic of one or more multicast traffic flows is received from a multicast source at a first provider edge router of a plurality of provider edge routers. A multicast routing message including a loopback address of the first provider edge router can be originated at the first provider edge router. The multicast routing message can be flooded into a multicast core network for controlling traffic in the one or more multicast flows through the multicast core network to the first provider edge router. Subsequently, multicast joins can be received at the first provider edge router for establishing the one or more multicast flows through the multicast core network based on the multicast routing message including the loopback address of the first provider edge router.

Abstract: In an example method for redundant multicast trees with fast recovery, a protocol independent multicast (PIM) backup designated router (BDR) can receive a request from a host to join a multicast group associated with a source; send to a next hop a PIM join message identifying an address of the PIM BDR and identifying the PIM join message as a backup PIM join; receive, from a PIM router along a path to/from the source, a unicast message sent to the address which identifies a second address associated with the PIM router; store the second address and a route associated with the unicast message; in response to a designated router migration trigger, set to blocking a backup multicast tree state associated with the source and multicast group; and send, to the PIM router, a unicast message including instructions to set to blocking a backup multicast tree state at the PIM router.

Abstract: In one illustrative example, a network node connected in a network fabric may identify that it is established as part of a multicast distribution tree for forwarding multicast traffic from a source node to one or more host receiver devices of a multicast group. In response, the network node may propagate in the network fabric a message for advertising the network node as a candidate local source node at which to join the multicast group. The message for advertising may include data such as a reachability metric. The propagation of the message may be part of a flooding of such messages in the network fabric. The network node serving as the candidate local source node may thereafter “locally” join a host receiver device in the multicast group at the network node so that the device may receive the multicast traffic from the source node via the network node.

Abstract: A method is performed by a first provider edge (PE) of a redundancy group including provider edges configured with an Ethernet virtual private network (EVPN) segment identifier (EVI) and an Ethernet segment identifier (ESI) and that are multi-homed to a customer edge (CE). The method includes, upon receiving from the CE a join request including a group address for a multicast stream, electing a designated forwarder (DF) for the multicast stream. The electing includes: computing for each PE a respective affinity for the DF as a function of a respective address of the PE, the EVI, and the group address; and determining which PE has a largest affinity. The method further includes, if the first PE has the largest affinity or does not have the largest affinity, configuring the first PE as the designated forwarder or not configuring the first PE as the designated forwarder for the multicast stream, respectively.

Abstract: A first network device joins a redundancy group of a multihomed network element that is connected to a computing device. The first network device detects an active link between the first network device and the computing device, and receives from the computing device, a subscription to a multicast flow. The first network device adds the subscription to a first list of active multicast subscriptions stored on the first network device. The first network device sends a unicast notification to a second network device of the multihomed network element. The unicast notification causes the subscription to be added to a second list of active multicast subscriptions stored on the second network device.