Configuring a multicast forwarding range, Configuring the multicast forwarding table size – H3C Technologies H3C SecPath F1000-E User Manual

Page 592

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Step

Command

Remarks

3.

Configure multicast load splitting. multicast load-splitting { source |

source-group }

Optional.
Disabled by default.

Configuring a multicast forwarding range

Multicast packets do not travel without a boundary in a network. The multicast data corresponding to

each multicast group must be transmitted within a definite scope.
You can configure a forwarding boundary specific to a particular multicast group on all interfaces that

support multicast forwarding. A multicast forwarding boundary sets the boundary condition for the

multicast groups in the specified range. If the destination address of a multicast packet matches the set

boundary condition, the packet will not be forwarded. After you configure an interface as a multicast
boundary, the interface can no longer forward multicast packets (including packets sent from the local

device) or receive multicast packets.
To configure a multicast forwarding range:

Step

Command

Remarks

1.

Enter system view.

system-view

N/A

2.

Enter interface view.

interface interface-type
interface-number

N/A

3.

Configure a multicast forwarding

boundary.

multicast boundary group-address
{ mask | mask-length }

No forwarding boundary
by default

Configuring the multicast forwarding table size

The router maintains the corresponding forwarding entry for each multicast packet that it receives.
Excessive multicast routing entries, however, can exhaust the router’s memory and cause lower router

performance. You can set a limit on the number of entries in the multicast forwarding table based on the

networking situation and the performance requirements. If the configured maximum number of multicast

forwarding table entries is smaller than the current value, the forwarding entries in excess will not be
deleted immediately. Instead, the multicast routing protocols that are running on the router will delete

them. The router will no longer add new multicast forwarding entries until the number of existing multicast

forwarding entries comes down under the configured value.
When forwarding multicast traffic, the router replicates a copy of the multicast traffic for each

downstream node and forwards the traffic. Thus, each of these downstream nodes forms a branch of the
multicast distribution tree. You can configure the maximum number of downstream nodes (namely, the

maximum number of outgoing interfaces) for a single entry in the multicast forwarding table to lessen the

burden on the router for replicating multicast traffic. If the configured maximum number of downstream

nodes for a single multicast forwarding entry is smaller than the current number, the downstream nodes
in excess will not be deleted immediately. Instead, the multicast routing protocols that are running on the

router will delete them. The router will no longer add new multicast forwarding entries for newly added

downstream nodes until the number of existing downstream nodes comes down under the configured

value.
To configure the multicast forwarding table size for the public network:

Step

Command

Remarks

1.

Enter system view.

system-view

N/A

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