3Com Router 3000 Ethernet FamilyConfiguration Guide Chapter 4 PIM Configuration3Com Corporation4-12If the entry (S, G) of a source group is denied or not defined by the ACL, or there is noACL, the RP will send RegisterStop information to the DR to stop the registration of thismulticast data stream.Caution:Only the register packets matching the ACL permit clause will be accepted by the RP.Specifying an undefined ACL will cause the RP to deny all register packets.4.3.14 Configuring the Threshold to Switch from RPT to SPTThe PIM-SM routers use the shared tree to forward multicast data packets initially. If thetraffic rate exceeds the specified threshold, the last hop router the packet passes willinitiate the switch from the shared tree to the shortest path tree.Perform the following configuration in PIM view.Table 4-14 Configure the threshold to switch from the RPT to the SPTOperation CommandSet the threshold to switch from the RPTto the SPTspt-switch-threshold { traffic-rate |infinity } [ group-policy acl-number ]Restore the default configuration undo spt-switch-threshold { traffic-rate| infinity } [ group-policy acl-number ]By default, the threshold is 0. In that case, the last hop router turns to the shortest pathtree when it receives the first multicast datagram.4.3.15 Configuring BSR PolicyTo prevent the valid BSRs from being maliciously replaced or BSR spoofing, BSRpolicy can be configured to specify the valid BSR range. Information from BSRs out ofthis range will not be accepted.Perform the following configuration in the appropriate view.Table 4-15 Configuring BSR policyOperation CommandSpecify the range of valid BSRs (in PIMview) bsr-policy acl-numberRestore the normal state without anyrange limitation (in PIM view) undo bsr-policy
