Operation Manual – MulticastH3C S5600 Series Ethernet Switches Chapter 5 MSDP Configuration5-12SA messages cannot be transmitted between these two peers. On the other hand,when resetting an MSDP peering relationship between faulty MSDP peers or bringingfaulty MSDP peers back to work, you can adjust the retry interval of establishing apeering relationship through the following configuration.Follow these steps to configure MSDP peer connection control:To do... Use the command... RemarksEnter system view system-view —Enter MSDP view msdp —Shut down the connectionwith the specified MSDPpeershutdownpeer-addressOptionalBy default, all MSDPpeering connections are up.Configure the retry intervalof MSDP peer connectionestablishmenttimer retry seconds Optional30 seconds by default5.4 Configuring SA Message TransmissionAn SA message contains the IP address of the multicast source S, multicast groupaddress G, and RP address. In addition, it contains the first multicast data received bythe RP in the domain where the multicast source resides. For some burst multicast data,if the multicast data interval exceeds the SA message hold time, the multicast datamust be encapsulated in the SA message; otherwise, the receiver will never receive themulticast source information.By default, when a new receiver joins, a router does not send any SA request messageto its MSDP peer but has to wait for the next SA message. This defers the reception ofthe multicast information by the receiver. In order for the new receiver to know aboutthe currently active multicast source as quickly as possible, the router needs to sendSA request messages to the MSDP peer.Generally, a router accepts all SA messages sent by all MSDP peers and sends all SAmessages to all MSDP peers. By configuring the rules for filtering SA messages toreceive/send, you can effectively control the transmission of SA messages amongMSDP peers. For forwarded SA messages, you can also configure a Time-to-Live (TTL)threshold to control the range where SA messages carrying encapsulated data aretransmitted.To reduce the delay in obtaining the multicast source information, you can cache SAmessages on the router. The number of SA messages cached must not exceed thesystem limit. The more messages are cached, the more router memory is occupied.
