Huawei Quidway s3700 series Configuration Manual page 207

Quidway S3700 Series Ethernet Switches
Configuration Guide - Multicast
PIM-SM Intra-Domain Anycast RP
After anycast RP is applied to a PIM-SM domain, the multicast source registers with the nearest
RP and receivers send Join messages to the nearest RP. This reduces the burden of a single RP,
implements RP backup, and optimizes the forwarding path.
You can use a loopback interface as a interface of C-RP or static RP and specify the logical RP
address for an SA message.
Configuring Control Parameters for Maintaining MSDP Peer Connections
In the S3700, you can set up and tear down an MSDP session, and configure the period for
retrying to send TCP connection requests to the remote MSDP peers.
Configuring SA Cache
By default, SA-Cache is enabled on switchs. Therefore, switchs can locally store the (S, G)
information carried in SA messages. When required to receive the multicast data, the switchs
can obtain the (S, G) information from the SA-Cache.
You can set the maximum number of cached (S, G) entries, which can effectively prevent the
Denial of Service (DoS) attack.
You can disable SA-Cache on a switch. After the SA-Cache on a switch is disabled, the
switch does not locally store the (S, G) information carried in SA messages. When the switch
needs to receive multicast data, it needs to wait for the SA message to be sent by its MSDP peer
in the next period. This causes a delay for receivers to obtain multicast source information.
Controlling SA Requests
Certain switchs cannot be enabled with SA Cache or the capacity of SA Cache on these
switchs is too small. When these switchs need to receive multicast data, they cannot immediately
obtain the valid (S, G) information but need to wait for the SA message to be sent by their MSDP
peers in the next period.
If SA Cache is enabled on the remote MSDP peer and the capacity of the SA Cache is large, you
can configure "sending SA request messages" on the local switch to reduce the period during
which receivers obtain multicast source information.
At the same time, you can also configure the filtering rules for receiving SA request messages
on the remote MSDP peers.
Transmitting Burst Multicast Data
When the interval for a certain multicast source to send multicast data is longer than the timeout
period of an (S, G) entry, the source DR can only encapsulate burst multicast data in Register
messages and send them to the source RP. The source RP uses SA messages to transmit (S, G)
information to the remote RP. The remote RP then sends an (S, G) Join message towards the
multicast source to create an SPT. Because of the timeout of the (S, G) entry, the remote user
cannot receive the multicast data sent by S.
The S3700 supports the transmission of burst multicast data. You can enable the function of
encapsulating a multicast data packet in an SA message on the source RP. The source RP can
then encapsulate multicast data in an SA message and send the message out. After receiving the
SA message, the remote RP decapsulates the message, and then forwards multicast data to hosts
in the domain along the RPT.
Issue 01 (2011-10-26) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
8 MSDP Configuration
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