Abstract: The disclosure describes techniques for enhancements to the Multicast Source Discovery Protocol (MSDP) to reduce Source Active (SA) message loops in one or more multicast domains having overlapping MSDP mesh groups. In some examples, a method includes receiving, by a first MSDP speaker, from a second MSDP speaker, a SA message. The method also includes, when the second MSDP speaker is in a mesh group with the first MSDP speaker, determining whether the first MSDP speaker includes an active SA state corresponding to the SA message. Additionally, the method includes, when the first MSDP speaker does not include the active SA state corresponding to the SA message, accepting the SA message and forwarding the SA message to a third MSDP speaker that is not in the mesh group with the first MSDP speaker and the second MSDP speaker.

Abstract: The disclosure describes techniques for enhancements to the Multicast Source Discovery Protocol (MSDP) to reduce Source Active (SA) message loops in one or more multicast domains having overlapping MSDP mesh groups. In some examples, a method includes receiving, by a first MSDP speaker, from a second MSDP speaker, a SA message. The method also includes, when the second MSDP speaker is in a mesh group with the first MSDP speaker, determining whether the first MSDP speaker includes an active SA state corresponding to the SA message. Additionally, the method includes, when the first MSDP speaker does not include the active SA state corresponding to the SA message, accepting the SA message and forwarding the SA message to a third MSDP speaker that is not in the mesh group with the first MSDP speaker and the second MSDP speaker.

Abstract: Multiple Register State Machines on a rendezvous point router (“RP”) in a Protocol Independent Multicast-Sparse Mode (“PIM-SM”) domain per (S,G) is supported, thereby increasing the Register state consistency and faster convergence in case of a first hop router (“FHR”) failure. Such example embodiments may advantageously eliminate the limitation of a single Register State Machine on RP for a given (S,G), in the presence of multiple FHRs connected to the same source. At least some such example embodiments provide the capability of maintaining multiple Register State Machines on RP for a given (S,G), in a way, that maps one Register State Machine to each FHR. In this way, the RP can avoid the inconsistent FHR states and traffic losses caused due to FHR failures.

Abstract: The potential problem of traffic loss during a period when a second PIM router is elected DR after a first PIM router (on the same PIM interface) was previously elected DR and is transiting multicast traffic, is solved by (1) configuring a first interval on a PIM interface for at least the first PIM router; (2) responsive to the PIM interface of the first PIM router booting up, (i) starting, by the first PIM router, a timer corresponding to the configured first interval, (ii) determining, by the first PIM router, whether or not it is the DR on the PIM interface, (iii) upon determining that the timer has expired, redetermining, by the first PIM router, whether or not it is the DR on the PIM interface, and (iv) responsive to a redetermination that the first PIM router is the DR on the PIM interface, (A) increasing, by the first PIM router, a DR priority value of the first PIM router to reduce a likelihood that another of the at least two PIM routers will replace the first PIM router as DR, and (B) sending on th