HP A5500 EI Switch Series, Руководство по настройке

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Multicast routing and forwarding configuration
(available only on the A5500 EI)
NOTE:
The term
router in this document refers to both routers and Layer 3 switches.
The interfaces in this document refer to Layer 3 interfaces in generic sense and Ethernet interfaces that
operate in route mode. For more information about the operating mode of the Ethernet interfaces, see
the
Layer 2—LAN Switching Configuration Guide.
Multicast routing and forwarding overview
Introduction to multicast routing and forwarding
In multicast implementations, the following types of tables implement multicast routing and forwarding:
•
Multicast routing table of a multicast routing protocol—Each multicast routing protocol has its own
multicast routing table, such as PIM routing table.
•
General multicast routing table—The multicast routing information of different multicast routing
protocols forms a general multicast routing table.
•
Multicast forwarding table—The multicast forwarding table guides the forwarding of multicast
packets.
A multicast routing table consists of a set of (S, G) entries. Each entry indicates the routing information
for delivering multicast data from a multicast source to a multicast group. If a router supports multiple
multicast protocols, its multicast routing table includes routes generated by multiple protocols. The router
chooses the optimal route from the multicast routing table based on the configured multicast routing and
forwarding policy and adds the route entry to its multicast forwarding table.
RPF check mechanism
A multicast routing protocol relies on the existing unicast routes, MBGP routes, or multicast static routes
in creating multicast routing entries. When creating multicast routing table entries, a multicast routing
protocol uses the RPF check mechanism to ensure multicast data delivery along the correct paths. In
addition, the RPF check mechanism also helps avoid data loops.
RPF check process
An RPF check is based on one of the following routing tables:
•
Unicast routing table—Contains the shortest path to each destination subnet
•
MBGP routing table—Contains multicast routing information
•
Multicast static routing table—Contains the RPF routing information defined by the user through
static configuration