Operation Manual – MulticastH3C S5600 Series Ethernet Switches Chapter 5 MSDP Configuration5-14Note:In Anycast RP application, a C-BSR and a C-RP must be configured on differentdevices or ports.5.4.3 Configuring SA Message CacheWith the SA message caching mechanism enabled on the router, the group that a newmember subsequently joins can obtain all active sources directly from the SA cacheand join the corresponding SPT source tree, instead of waiting for the next SAmessage.You can configure the number of SA entries cached in each MSDP peer on the routerby executing the following command, but the number must be within the system limit.To protect a router against Denial of Service (DoS) attacks, you can manually configurethe maximum number of SA messages cached on the router. Generally, the configurednumber of SA messages cached should be less than the system limit.Follow these steps to configure SA message cache:To do... Use the command... RemarksEnter system view system-view —Enter MSDP view msdp —Enable SA messagecaching mechanism cache-sa-enable OptionalEnabled by defaultConfigure the maximumnumber of SA messagesthat can be cachedpeer peer-addresssa-cache-maximumsa-limitOptionalThe default is 2,048.5.4.4 Configuring the Transmission and Filtering of SA Request MessagesAfter you enable the sending of SA request messages, when a router receives a Joinmessage, it sends an SA request message to the specified remote MSDP peer, whichresponds with an SA message that it has cached. After sending an SA requestmessage, the router will get immediately a response from all active multicast sources.The SA message that the remote MSDP peer sends in response is cached in advance;therefore, you must enable the SA message caching mechanism in advance. Typically,only the routers caching SA messages can respond to SA request messages.After you have configured a rule for filtering received SA messages, if no ACL isspecified, all SA request messages sent by the corresponding MSDP peer will beignored; if an ACL is specified, the SA request messages that satisfy the ACL rule arereceived while others are ignored.
