HP 6400cl, Management Manual, Page: 130 / 664

PIM-DM (Dense Mode) on the 5300xl Switches
Feature Overview
Feature Overview
PIM-DM on the Switch Series 5300XL devices includes:
■ Routing Protocol Support:
PIM uses whichever unicast routing proto­
col is running on the routing switch. These can include:
• RIP
• OSPF
• Static routes
• Directly connected interfaces
■ Interface Support: PIM-DM supports up to 127 outbound VLANs (and 1
inbound VLAN) in its multicast routing table (MRT) at any given time,
meaning that the sum of all outbound VLANs across all current flows on
a routing switch may not exceed 63. (A single flow may span one inbound
VLAN and up to 63 outbound VLANs, depending on the VLAN member-
ships of the hosts actively belonging to the flow.)
■ IGMP Compatibility:
PIM-DM is compatible with IGMP versions 1 - 3,
and is fully interoperable with IGMP for determining multicast flows.
■ XRRP: PIM-DM is fully interoperable with XRRP to quickly transition
multicast routes in the event of a failover.
■ MIB Support:
With some exceptions, PIM-DM supports the parts of the
Multicast Routing MIB applicable to PIM-DM operation. (Refer to “Excep­
tions to Support for RFC 2932 - Multicast Routing MIB” on page 5-41.)
■ PIM Draft Specifications: Compatible with PIM-DM draft specification,
versions 1 and 2.
PIM-DM Operation
PIM-DM operates at the router level to direct traffic for a particular multicast
group along the most efficient path to the VLANs having hosts that have joined
that group. A unicast source address and a multicast group address comprise
a given source/group (S/G) pair. Multicast traffic moving from a source to a
multicast group address creates a
flow to the area(s) of the network requiring
the traffic. That is, the flow destination is the multicast group address, and not
a specific host or VLAN. Thus, a single multicast flow has one source and one
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