3Com Switch 7750 SeriesCommand Reference Guide – Multicast Chapter 5 PIM Configuration Commands5-17undo spt-switch-threshold { traffic-rate | infinity } [ group-policy acl-number ]ViewPIM viewParametertraffic-rate: Rate of sending multicast packets in kbps, in the range of 0 to 65,535. Thethreshold for RPT-to-SPT switchover is 0 by default.infinity: Specifies not to switch traffic from RPT to SPT forever.acl-number: Number of a basic ACL, in the range of 2,000 to 2,999. This argumentdefines a group range. The rate of multicast packets in the range is limited.DescriptionUse the spt-switch-threshold command to set the threshold for RPT-to-SPTswitchover.Use the undo spt-switch-threshold command to restore the threshold to the defaultvalue.In PIM-SM, an Ethernet switch forwards multicast packets over RPT initially. If themulticast traffic sent by the multicast source exceeds the threshold value, the multicasttraffic will be switched from RPT to SPT when it passes the last-hop Ethernet switch.Note:Currently, the threshold value can be 0 or infinity.z If the threshold is to 0, the last-hop router will start RPT-to-SPT switchover when itreceives the first multicast packet.z If the threshold is set to infinity, the RPT-to-SPT switchover will never beperformed.Example# Specify the last-hop router to start RPT-to-SPT switchover as soon as it receives thefirst multicast packet.<3Com> system-viewSystem View: return to User View with Ctrl+Z.[3Com] pim[3Com-pim] spt-switch-threshold 0
