HP VPN Firewall Appliances Network Management Configuration Guide

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Configuring PIM
Overview
PIM provides IP multicast forwarding by leveraging unicast static routes or unicast routing tables
generated by any unicast routing protocol, such as RIP, OSPF, IS-IS, or BGP. Independent of the unicast
routing protocols running on the device, multicast routing can be implemented as long as the
corresponding multicast routing entries are created through unicast routes. PIM uses the RPF mechanism
to implement multicast forwarding. When a multicast packet arrives on an interface of the device, it
undergoes an RPF check. If the RPF check succeeds, the device creates the corresponding routing entry
and forwards the packet. If the RPF check fails, the device discards the packet. For more information
about RPF, see Appendix Protocol References
Based on the implementation mechanism, PIM includes the following categories:
• Protocol Independent Multicast–Dense Mode (PIM-DM)
• Protocol Independent Multicast–Sparse Mode (PIM-SM)
• Protocol Independent Multicast Source-Specific Multicast (PIM-SSM)
The term "router" in this document refers to both routers and routing-capable firewalls.
Configuring PIM in the Web interface
Before you configure PIM, configure a unicast routing protocol so that all devices in the domain are
interoperable at the network layer.
Recommended configuration procedure for PIM-DM
Ste
p
Remarks
1. Globally enabling multicast routing
Required.
Globally enable multicast routing after selecting Network >
Routing Management > Multicast Routing. For more information,
see "Configuring multicast routing and forwarding."
By default, multic
ast routing is globally disabled.
2. Configuring PIM interfaces
Required.
Enable PIM-DM on an interface.
After PIM-DM is enabled, a router sends hello messages
periodically to discover PIM neighbors and processes messages
from the PIM neighbors. When you deploy a PIM-DM domain,
enable PIM-DM on all non-border interfaces of the routers.
By default, PIM is disabled on an interface.
3. Displaying PIM neighbor information
Optional.