Abstract: In some examples, a method includes receiving, by an egress network device for a network, messages from each of a plurality of ingress network devices for the network, wherein each of the messages specifies a multicast source, a multicast group, and an upstream multicast hop weight value for multicast traffic for the multicast source and the multicast group; selecting, by the egress network device and based on the upstream multicast hop weight values specified by the received messages, one of the plurality of ingress network devices to which to send a multicast join message of a plurality of multicast join messages for the multicast source and multicast group; and sending, by the egress network device, the multicast join message to the selected one of the plurality of ingress network devices.

Abstract: In some examples, a method includes receiving, by an egress network device for a network, messages from each of a plurality of ingress network devices for the network, wherein each of the messages specifies a multicast source, a multicast group, and an upstream multicast hop weight value for multicast traffic for the multicast source and the multicast group; selecting, by the egress network device and based on the upstream multicast hop weight values specified by the received messages, one of the plurality of ingress network devices to which to send a multicast join message of a plurality of multicast join messages for the multicast source and multicast group; and sending, by the egress network device, the multicast join message to the selected one of the plurality of ingress network devices.

Abstract: In some examples, a method includes receiving, by an egress network device for a network, messages from each of a plurality of ingress network devices for the network, wherein each of the messages specifies a multicast source, a multicast group, and an upstream multicast hop weight value for multicast traffic for the multicast source and the multicast group; selecting, by the egress network device and based on the upstream multicast hop weight values specified by the received messages, one of the plurality of ingress network devices to which to send a multicast join message of a plurality of multicast join messages for the multicast source and multicast group; and sending, by the egress network device, the multicast join message to the selected one of the plurality of ingress network devices.

Abstract: In some examples, a method includes receiving, by an egress network device for a network, messages from each of a plurality of ingress network devices for the network, wherein each of the messages specifies a multicast source, a multicast group, and an upstream multicast hop weight value for multicast traffic for the multicast source and the multicast group; selecting, by the egress network device and based on the upstream multicast hop weight values specified by the received messages, one of the plurality of ingress network devices to which to send a multicast join message of a plurality of multicast join messages for the multicast source and multicast group; and sending, by the egress network device, the multicast join message to the selected one of the plurality of ingress network devices.

Abstract: In some examples, a method includes receiving, by an egress network device for a network, messages from each of a plurality of ingress network devices for the network, wherein each of the messages specifies a multicast source, a multicast group, and an upstream multicast hop weight value for multicast traffic for the multicast source and the multicast group; selecting, by the egress network device and based on the upstream multicast hop weight values specified by the received messages, one of the plurality of ingress network devices to which to send a multicast join message of a plurality of multicast join messages for the multicast source and multicast group; and sending, by the egress network device, the multicast join message to the selected one of the plurality of ingress network devices.

Abstract: In some examples, a method includes receiving, by an egress network device for a network, messages from each of a plurality of ingress network devices for the network, wherein each of the messages specifies a multicast source, a multicast group, and an upstream multicast hop weight value for multicast traffic for the multicast source and the multicast group; selecting, by the egress network device and based on the upstream multicast hop weight values specified by the received messages, one of the plurality of ingress network devices to which to send a multicast join message of a plurality of multicast join messages for the multicast source and multicast group; and sending, by the egress network device, the multicast join message to the selected one of the plurality of ingress network devices.

Abstract: Techniques are described for dynamically computing a segment routing policy for a segment routing for traffic engineering (SR-TE) path. For example, in a discontinuous SR network in which SR islands (e.g., groups of neighboring routers that are enabled for segment routing) are separated by one or more routers not enabled for segment routing, instead of returning a failure because one or more routers along a path are not enabled for SR, an ingress router may generate an SR-TE operations, administrations, and management (OAM) Multi-Protocol Label Switching (MPLS) traceroute packet send the packet to a first border router of the RSVP-enabled devices along a computed path to trigger the creation of a resource reservation Label Switched Path (LSP) through the RSVP-enabled devices. In this way, segment routed LSP may be established to tunnel through the resource reservation LSP for a SR-TE path used in an SR-TE policy.

Abstract: An example network device includes a memory; and processing circuitry configured to: determine a primary path between the network device and a second network device; determine candidate backup paths between the network device and the second network device; in response to a determination that a first candidate backup path of the candidate backup paths satisfies a first priority criteria, select the first candidate backup path as a backup path; in response to a determination that a second candidate backup path of the candidate backup paths satisfies a second priority criteria, select the second candidate backup path as the backup path; and program a packet processor of the network device with the primary path and the backup path. The first priority criteria and the second priority criteria can be based on a risk of simultaneous failure of the primary path and a candidate backup path of the plurality of backup path.

Abstract: In some examples, a network device may determine whether a first egress network device is segment routing (SR) aware. Based on the first egress network device being SR aware, the network device may initiate establishment of an SR tunnel toward the first egress network device. The network device may forward multicast traffic on the SR tunnel. The network device may also determine whether a second egress network device is SR aware. Based on the second egress network device not being segment routing aware, the network device may initiate establishment of a non-SR tunnel toward the second egress network device. The network device may forward multicast traffic on the non-SR tunnel.

Abstract: In some examples, a method includes receiving, by an egress network device for a network, messages from each of a plurality of ingress network devices for the network, wherein each of the messages specifies a multicast source, a multicast group, and an upstream multicast hop weight value for multicast traffic for the multicast source and the multicast group; selecting, by the egress network device and based on the upstream multicast hop weight values specified by the received messages, one of the plurality of ingress network devices to which to send a multicast join message of a plurality of multicast join messages for the multicast source and multicast group; and sending, by the egress network device, the multicast join message to the selected one of the plurality of ingress network devices.

Abstract: In some examples, a network device may determine whether a first egress network device is segment routing (SR) aware. Based on the first egress network device being SR aware, the network device may initiate establishment of an SR tunnel toward the first egress network device. The network device may forward multicast traffic on the SR tunnel. The network device may also determine whether a second egress network device is SR aware. Based on the second egress network device not being segment routing aware, the network device may initiate establishment of a non-SR tunnel toward the second egress network device. The network device may forward multicast traffic on the non-SR tunnel.

Abstract: Techniques are described for avoiding traffic loss in a network when a designated router (DR) for a L2 broadcast communication domain loses its route toward a multicast traffic source. The disclosed techniques may be utilized in a scenario where a receiver is multi-homed to a DR network device and a non-DR network device by a L2 broadcast communication domain. Both the DR and the non-DR network devices receive a request from the receiver identifying a multicast group in which the receiver is interested. The non-DR network device monitors traffic injected into the L2 broadcast communication domain by the DR in order to determine whether the DR has lost the route to the source of the multicast group. If the DR has lost the route, the non-DR network device performs a repair by sending the multicast data traffic for the multicast group to the receiver on the L2 broadcast communication domain.

Abstract: Techniques are described for enhancements to Protocol Independent Multicast (PIM) to support multicast only fast re-route (MoFRR) over a remote loop free alternate (RLFA) backup path in a network. This disclosure describes a modified PIM control message having a new PIM message type and an additional field to indicate an address of a RLFA network device in the RLFA backup path. According to techniques of this disclosure, network devices along the RLFA backup path are configured to forward the modified PIM control message toward the RLFA network device instead of toward a source of a requested multicast group. When the RLFA network device receives the modified PIM control message, the RLFA network device is configured to forward a conventional PIM control message towards the source of the requested multicast group. In this way, PIM can be used to provide MoFRR over a RLFA backup path.

Abstract: Techniques are described for enhancements to Protocol Independent Multicast (PIM) to support multicast only fast re-route (MoFRR) over a remote loop free alternate (RLFA) backup path in a network. This disclosure describes a modified PIM control message having a new PIM message type and an additional field to indicate an address of a RLFA network device in the RLFA backup path. According to techniques of this disclosure, network devices along the RLFA backup path are configured to forward the modified PIM control message toward the RLFA network device instead of toward a source of a requested multicast group. When the RLFA network device receives the modified PIM control message, the RLFA network device is configured to forward a conventional PIM control message towards the source of the requested multicast group. In this way, PIM can be used to provide MoFRR over a RLFA backup path.

Abstract: Techniques are described for enhancements to Protocol Independent Multicast (PIM) to support multicast only fast re-route (MoFRR) over a remote loop free alternate (RLFA) backup path in a network. This disclosure describes a modified PIM control message having a new PIM message type and an additional field to indicate an address of a RLFA network device in the RLFA backup path. According to techniques of this disclosure, network devices along the RLFA backup path are configured to forward the modified PIM control message toward the RLFA network device instead of toward a source of a requested multicast group. When the RLFA network device receives the modified PIM control message, the RLFA network device is configured to forward a conventional PIM control message towards the source of the requested multicast group. In this way, PIM can be used to provide MoFRR over a RLFA backup path.

Abstract: Techniques are described for enhancements to Protocol Independent Multicast (PIM) to support multicast only fast re-route (MoFRR) over a remote loop free alternate (RLFA) backup path in a network. This disclosure describes a modified PIM control message having a new PIM message type and an additional field to indicate an address of a RLFA network device in the RLFA backup path. According to techniques of this disclosure, network devices along the RLFA backup path are configured to forward the modified PIM control message toward the RLFA network device instead of toward a source of a requested multicast group. When the RLFA network device receives the modified PIM control message, the RLFA network device is configured to forward a conventional PIM control message towards the source of the requested multicast group. In this way, PIM can be used to provide MoFRR over a RLFA backup path.