46-37
Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter46 Configuring IP Multicast Routing
Configuring Advanced PIM Features
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.
Modifying the PIM Router-Query Message Interval
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.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 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.
Step3 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.
Note 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.
Step4 end Return to privileged EXEC mode.
Step5 show running-config Verify your entries.
Step6 copy running-config startup-config (Optional) Save your entries in the configuration file.