Cisco Systems 3560 사용자 설명서

Beginning in privileged EXEC mode, follow these steps to configure a traffic rate threshold that must 
be reached before multicast routing is switched from the source tree to the shortest-path tree. This 
procedure is optional.

To return to the default setting, use the no ip pim spt-threshold {kbps | infinity} global configuration 
command.

PIM routers and multilayer switches send PIM router-query messages to find which device is the DR for 
each LAN segment (subnet). The DR is responsible for sending IGMP host-query messages to all hosts 
on the directly connected LAN. 

Enter global configuration mode.

access-list access-list-number {deny | 
permit} source [source-wildcard]

Create a standard access list.

For access-list-number, the range is 1 to 99.

The deny keyword denies access if the conditions are matched. 
The permit keyword permits access if the conditions are 
matched.

For source, specify the multicast group to which the threshold 
applies.

(Optional) For source-wildcard, enter the wildcard bits in dotted 
decimal notation to be applied to the source. Place ones in the 
bit positions that you want to ignore.

Recall that the access list is always terminated by an implicit deny 
statement for everything.

ip pim spt-threshold {kbps | infinity} 
[group-list access-list-number]

Specify the threshold that must be reached before moving to 
shortest-path tree (spt).

For kbps, specify the traffic rate in kilobits per second. The 
default is 0 kb/s. 

Because of switch hardware limitations, 0 kb/s is the only 
valid entry even though the range is 0 to 4294967.

Specify infinity if you want all sources for the specified group 
to use the shared tree, never switching to the source tree.

(Optional) For group-list access-list-number, specify the access 
list created in Step 2. If the value is 0 or if the group-list is not 
used, the threshold applies to all groups.

Return to privileged EXEC mode.

Verify your entries.

(Optional) Save your entries in the configuration file.