Configuring Multicast Routing And Forwarding - 3Com Switch 4800G 24-Port Configuration Manual

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HAPTER ULTICAST
Configuring Multicast
Routing and
Forwarding
Configuration
Prerequisites
Enabling IP Multicast
Routing
Configuring Multicast
Static Routes
R F
OUTING AND ORWARDING
Before configuring multicast routing and forwarding, complete the following
tasks:
Configure a unicast routing protocol so that all devices in the domain are
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interoperable at the network layer.
Enable PIM (PIM-DM or PIM-SM).
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Before configuring multicast routing and forwarding, prepare the following data:
The minimum TTL value required for a multicast packet to be forwarded
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The maximum number of downstream nodes for a single route in a multicast
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forwarding table
The maximum number of routing entries in a multicast forwarding table
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Before configuring any Layer 3 multicast functionality, you must enable IP
multicast routing.
Follow these steps to enable IP multicast routing:
To do...
Enter system view
Enable IP multicast routing
c
CAUTION: IP multicast does not support the use of secondary IP address
segments. Namely, multicast can be routed and forwarded only through primary IP
addresses, rather than secondary addresses, even if configured on interfaces.
For details about primary and secondary IP addresses, refer to "IP Addressing
Configuration" on page 121.
Based on the application environment, a multicast static route has the following
two functions:
Changing an RPF route. If the multicast topology structure is the same as the
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unicast topology in a network, the delivery path of multicast traffic is the same
as in unicast. By configuring a multicast static route, you can change the RPF
route so as to create a transmission path that is different from the unicast
traffic transmission path.
Creating an RPF route. When a unicast route is interrupted, multicast traffic
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forwarding is stopped due to lack of an RPF route. By configuring a multicast
static route, you can create an RPF route so that a multicast routing entry is
created to guide multicast traffic forwarding.
Follow these steps to configure a multicast static route:
C
ONFIGURATION
Use the command...
system-view
multicast routing-enable
Remarks
-
Required
Disable by default