R3303-HP HSR6800 Routers IP Multicast Configuration Guide

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Configuring a multicast forwarding range
Multicast packets do not travel without a boundary in a network. The multicast data of each multicast
group must be transmitted within a definite scope.
You can configure a forwarding boundary specific to a 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 for a multicast group, the interface will not
receive or forward multicast packets of this multicast group, or forward locally generated multicast
packets.
To configure a multicast forwarding range:
Ste
p
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.
However, excessive multicast routing entries can exhaust the router's memory and cause lower
performance.
You can set the maximum number of entries in the multicast forwarding table according to the networking
situation and the performance requirements. If the configured upper limit is smaller than the number of
existing entries in the multicast forwarding table, the entries in excess are not deleted immediately. The
multicast routing protocol that runs on the router will delete them. The router will no longer add new
multicast forwarding entries until the number of existing multicast forwarding entries decreases below the
upper limit.
When the router forwards multicast data, it replicates a copy of the multicast data for each downstream
node and forwards the data. Each of these downstream nodes is 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.
If the configured upper limit is smaller than the number of existing downstream nodes for a forwarding
entry, the downstream nodes in excess are not deleted immediately. The multicast routing protocol that
runs on the router will delete them. The router will no longer update the newly added downstream nodes
for the forwarding entry until the number of existing downstream nodes for the forwarding entry
decreases below the upper limit.
Configuring the multicast forwarding table size for the public network