10z Before you configure an MSDP mesh group, make sure that the routers are fully connected withone another.z The same group name must be configured on all the peers before they can join a mesh group.z If you add the same MSDP peer to multiple mesh groups, only the latest configuration takes effect.Configuring MSDP Peer Connection ControlThe connection between MSDP peers can be flexibly controlled. You can disable the MSDP peeringrelationships temporarily by shutting down the MSDP peers. As a result, SA messages cannot betransmitted between these two peers. On the other hand, when resetting an MSDP peering relationshipbetween faulty MSDP peers or bringing faulty MSDP peers back to work, you can adjust the retryinterval of establishing a peering 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 connection withthe specified MSDP peer shutdown peer-addressOptionalBy default, all MSDP peeringconnections are up.Configure the retry interval ofMSDP peer connectionestablishmenttimer retry seconds Optional30 seconds by defaultConfiguring SA Message TransmissionAn SA message contains the IP address of the multicast source S, multicast group address G, and RPaddress. In addition, it contains the first multicast data received by the RP in the domain where themulticast source resides. For some burst multicast data, if the multicast data interval exceeds the SAmessage hold time, the multicast data must be encapsulated in the SA message; otherwise, thereceiver will never receive the multicast source information.By default, when a new receiver joins, a router does not send any SA request message to its MSDPpeer but has to wait for the next SA message. This defers the reception of the multicast information bythe receiver. In order for the new receiver to know about the currently active multicast source as quicklyas possible, the router needs to send SA request messages to the MSDP peer.Generally, a router accepts all SA messages sent by all MSDP peers and sends all SA messages to allMSDP peers. By configuring the rules for filtering SA messages to receive/send, you can effectivelycontrol the transmission of SA messages among MSDP peers. For forwarded SA messages, you canalso configure a Time-to-Live (TTL) threshold to control the range where SA messages carryingencapsulated data are transmitted.
