Huawei Quidway s3700 series Configuration Manual page 250

Quidway S3700 Series Ethernet Switches
Configuration Guide - Multicast
Static Multicast Route
The static multicast route is an important factor of RPF check. By configuring the static multicast
route, users can specify the RPF interface and RPF neighbor for a specific source of packets on
the current switch.
The static multicast route cannot be used to forward data. It only affects RPF check, and is also
called static RPF route.
The static multicast route is valid only on the configured multicast switchs, and cannot be
advertised or imported to other switchs.
Multicast Routing Policy
If multiple unicast routes with the same cost exist when a multicast switch selects an upstream
interface, users can use one of following methods to configure the switch to select the RPF route:
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Controlling the Multicast Forwarding Range
In a network, the multicast information to which each multicast group corresponds is transmitted
in a certain range. Users can define the multicast forwarding range by using the following
method:
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Controlling the Capacity of a Multicast Forwarding Table
When planning a specific network according to network services, the Internet Service Provider
(ISP) can perform the following configurations:
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Issue 01 (2011-10-26)
By default, the switch chooses the route with the largest next-hop address.
According to the longest match, the switch selects the route longest matching the address
of the source of the packet.
Load splitting is configured among equal-cost routes. Performing load splitting of multicast
traffic according to different policies can optimize network traffic transmission in the
scenario where multiple multicast data flows exist.
There are five multicast load splitting policies: stable-preferred, balance-preferred, source
address-based, group address-based, and source and group addresses-based. The five load
splitting policies are mutually exclusive. In stable-preferred mode and balance-preferred
mode, you can configure load splitting weights on the interfaces to achieve unbalanced
multicast load splitting.
Configuring a multicast forwarding boundary on an interface to form a closed multicast
forwarding area.
Limiting the number of entries in the multicast forwarding table
Each switch maintains a forwarding entry for each received multicast packet. Too many
multicast forwarding entries, however, use up the memory of a switch. Users can define
the maximum number of entries in the multicast forwarding table of a switch. Limiting the
number of entries according to the actual networking and service performance can avoid
switch faults caused by excessive entries.
Limiting the number of downstream nodes of each forwarding entry
Switch replicate a multicast packet for each downstream node, and then send it out. Each
downstream node forms a branch of an MDT. The number of downstream nodes determines
the maximum scale of the MDT and the multicast service range. Users can define the
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