H3C Technologies H3C S12500 Series Switches - Manual (Page 83)

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Configuring a multicast routing policy in a VPN instance
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter VPN instance view. ip vpn-instance vpn-instance-name N/A
3. Configure the device to select
the RPF route based on the
longest match.
multicast longest-match
The route with the highest priority is
selected as the RPF route by
default.
4. Configure multicast load
splitting.
multicast load-splitting { source |
source-group }
Optional.
Disabled by default.
NOTE:
This command does not take effect
on BIDIR-PIM.
Configuring a multicast forwarding range
Multicast packets do not travel infinitely in a network. The multicast data corresponding to each multicast
group must be transmitted within a definite scope. You can define a multicast forwarding range by
specifying boundary interfaces, which form a closed multicast forwarding area.
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 boundary:
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.
However, excessive multicast routing entries 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.