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Cisco Catalyst Switch Module 3110 and 3012 for IBM BladeCenter Software Configuration Guide
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Chapter 38 Configuring IP Unicast Routing
Configuring Stub Routing
PIM Stub Routing Configuration Guidelines
Follow these guidelines when enabling PIM stub routing on an interface:
• Before configuring PIM stub routing, you must have IP multicast routing configured on both the stub
router and the central router. You must also have PIM mode (dense-mode, sparse-mode, or
dense-sparse-mode) configured on the uplink interface of the stub router.
• The PIM stub router does not route traffic between the distribution routers. Unicast (EIGRP) stub
routing manages this behavior. You must configure unicast stub routing to assist the PIM stub router
behavior. For more information, see the “Configuring EIGRP Stub Routing” section on page 38-30.
• Only directly connected multicast (IGMP) receivers and sources are allowed in the Layer 2 access
domains. The PIM protocol is not supported in access domains.
• The redundant PIM stub router topology is not supported.
Enabling PIM Stub Routing
Beginning in privileged EXEC mode, follow these steps to enable PIM stub routing on an interface. This
procedure is optional.
To disable PIM stub routing on an interface, use the no ip pim passive interface configuration command.
In this example, IP multicast routing is enabled. The PIM uplink port 25 on Switch A is configured as a
routed uplink port with spare-dense-mode enabled. PIM stub routing is enabled on the VLAN 100
interfaces and on Gigabit Ethernet port 20 in Figure 38-4:
Switch(config)# ip multicast-routing distributed
Switch(config)# interface gigabitethernet1/0/25
Switch(config-if)# no switchport
Switch(config-if)# ip address 3.1.1.2 255.255.255.0
Switch(config-if)# ip pim sparse-dense-mode
Switch(config-if)# exit
Switch(config)# interface vlan100
Switch(config-if)# ip pim passive
Switch(config-if)# exit
Switch(config)# interface gigabitethernet1/0/20
Switch(config-if)# ip pim passive
Switch(config-if)# exit
Switch(config)# interface vlan100
Switch(config-if)# ip address 100.1.1.1 255.255.255.0
Switch(config-if)# ip pim passive
Switch(config-if)# exit
Switch(config)# interface gigabitethernet1/0/20
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
interface interface-id Specify the interface on which you want to enable PIM stub routing, and
enter interface configuration mode.
Step 3
ip pim passive Configure the PIM stub feature on the interface.
Step 4
end Return to privileged EXEC mode.
Step 5
show ip pim interface Display the PIM stub that is enabled on each interface.
Step 6
show running-config Verify your entries.
Step 7
copy running-config startup-config (Optional) Save your entries in the configuration file.
