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Software Configuration Guide—Release 12.2(25)SG
OL-7659-03
Chapter24 Understanding and Conf iguring IP Multicast
Monitoring and Maintaining IP Multicast Routing
When an interface is treated in dense mode, it is populated in a multicast routing table’s outgoing
interface list when either of the following is true:
•When there are members or DVMRP neighbors on the interface
•When there are PIM neighbors and the group has not been pruned
When an interface is treated in sparse mode, it is populated in a multicast routing table’s outgoing
interface list when either of the following is true:
•When there are members or DVMRP neighbors on the interface
•When an explicit join has been received by a PIM neighbor on the interface
To enable PIM to operate in the same mode as the group, perform this task:
Monitoring and Maintaining IP Multicast Routing
You can remove all contents of a particular cache, table, or database. You also can display specific
statistics. The following sections describe how to monitor and maintain IP multicast:
•Displaying System and Network Statistics, page 24-15
•Displaying the Multicast Routing Table, page 24-16
•Displaying IP MFIB, page 24-18
•Displaying IP MFIB Fast Drop, page 24-19
•Displaying PIM Statistics, page 24-20
•Clearing Tables and Databases, page 24-20

Displaying System and Network Statistics

You can display specific statistics, such as the contents of IP routing tables and databases. Information
provided can be used to determine resource utilization and solve network problems. You can also display
information about node reachability and discover the routing path your device’s packets are taking
through the network.
To display various routing statistics, you can perform any of these tasks:
Command Purpose
Switch(config-if)# ip pim
sparse-dense-mode
Enables PIM to operate in sparse or dense mode,
depending on the group.
Command Purpose
Switch# ping [
group-name
|
group-address
]Sends an ICMP Echo Request to a multicast
group address.
Switch# show ip mroute [
hostname
|
group_number
]
Displays the contents of the IP multicast routing
table.
Switch# show ip pim interface [
type number
]
[count]
Displays information about interfaces configured
for PIM.
Switch# show ip interface Displays PIM information for all interfaces.