3Com 7750 Series Command Reference Manual page 588

3Com Switch 7750 Series
Command Reference Guide – Multicast
undo spt-switch-threshold { traffic-rate | infinity } [ group-policy acl-number ]
View
PIM view
Parameter
traffic-rate: Rate of sending multicast packets in kbps, in the range of 0 to 65,535. The
threshold 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 argument
defines a group range. The rate of multicast packets in the range is limited.
Description
Use the spt-switch-threshold command to set the threshold for RPT-to-SPT
switchover.
Use the undo spt-switch-threshold command to restore the threshold to the default
value.
In PIM-SM, an Ethernet switch forwards multicast packets over RPT initially. If the
multicast traffic sent by the multicast source exceeds the threshold value, the multicast
traffic 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.
If the threshold is to 0, the last-hop router will start RPT-to-SPT switchover when it
receives the first multicast packet.
If the threshold is set to infinity, the RPT-to-SPT switchover will never be
performed.
Example
# Specify the last-hop router to start RPT-to-SPT switchover as soon as it receives the
first multicast packet.
<3Com> system-view
System View: return to User View with Ctrl+Z.
[3Com] pim
[3Com-pim] spt-switch-threshold 0
Chapter 5 PIM Configuration Commands
5-17