Protocol Independent Multicast (PIM) is an intra-domain multicast routing protocol that uses unicast routing information to perform reverse path forwarding (RPF) checks on multicast packets and to create multicast routing entries. PIM can dynamically respond to network topology changes and maintain multicast forwarding tables.
This section describes how to configure Protocol Independent Multicast-Dense Mode (PIM-DM). On a small network with densely distributed members, there can be members on each network segment. PIM-DM can be used to construct and maintain a multicast distribution tree to forward multicast data.
On a PIM-SM network, any sender can be a multicast source, and receivers cannot know multicast source addresses before they join multicast groups. A Rendezvous Point (RP) is the forwarding core on a PIM-SM network. RPs are categorized as static RPs or BootStrap router (BSR) RPs, responsible for collecting multicast source information and group member information.
Before configuring PIM inter-domain multicast, configure BootStrap router (BSR) boundaries to divide a multicast network into different PIM-SM domains. Each BSR serves only the local PIM-SM domain, and routers outside the BSR boundary of a PIM-SM domain do not take part in BSR message forwarding in this PIM-SM domain.
The PIM-SSM model provides the source-specific transmission service for receivers. In PIM-SSM, a dedicated multicast forwarding path is set up directly between a source and a receiver.
Anycast-RP is a feature supporting the configuration of several Rendezvous Points (RPs) with the same address in a PIM-SM domain. Peer relationships are established between RPs so that IP routing can automatically select the topologically closest RP for each source and receiver. This alleviates burdens on RPs, implements RP backup, and optimizes multicast forwarding paths.
After detecting a fault on a peer, BFD immediately instructs the PIM module to trigger a new Designated router (DR) election rather than waits until the neighbor relationship times out. This minimizes the multicast data interruptions and improves the reliability of multicast data transmission.
Point-to-multipoint (P2MP) traffic engineering (TE) is a promising solution to multicast service transmission. P2MP TE helps carriers provide high TE capabilities and increased reliability on an IP/MPLS backbone network and reduce network operational expenditure (OPEX).
This section describes how to configure multicast source cloning-based PIM fast reroute (FRR) to provide E2E node and link protection for multicast services.
If you want to authenticate sent and received IPv4 PIM messages, configure IPv4 PIM IP Security (IPsec). IPv4 PIM IPsec protects a device against attacks launched using forged IPv4 PIM messages.
You can configure whitelist session-CAR for PIM to isolate bandwidth resources by session for PIM messages. This configuration prevents bandwidth preemption among PIM sessions in the case of a traffic burst.
Maintaining PIM involves querying statistics about the outbound interfaces of IPv4 PIM SM entries, clearing PIM statistics, monitoring PIM running status, and locating faults through PIM debugging information.