Configuring A Single Static Rp - Cisco Catalyst 4500 Series Configuration Manual

Configuring IP Multicast Routing
Switch# show ip pim rp mapping
Switch# show ip igmp groups
Switch# show ip mroute cbone-audio

Configuring a Single Static RP

If you are configuring PIM sparse mode, you must configure a PIM RP for a multicast group. An RP can
either be configured statically in each device, or learned through a dynamic mechanism. This task
explains how to statically configure an RP, as opposed to the router learning the RP through a dynamic
mechanism such as Auto-RP.
PIM designated routers (DRs) forward data from directly connected multicast sources to the RP for
distribution down the shared tree. Data is forwarded to the RP in one of two ways. It is encapsulated in
register packets and unicast directly to the RP, or, if the RP has itself joined the source tree, it is multicast
forwarded per the RPF forwarding algorithm. Last hop routers directly connected to receivers may, at
their discretion, join themselves to the source tree and prune themselves from the shared tree.
A single RP can be configured for multiple groups that are defined by an access list. If no RP is
configured for a group, the router treats the group as dense using the PIM dense mode techniques. (You
can prevent this occurrence by configuring the no ip pim dm-fallback command.)
If a conflict exists between the RP configured with the ip pim rp-address command and one learned by
Auto-RP, the Auto-RP information is used, unless the override keyword is configured.
To configure a single static RP, perform this task:
Command or Action
Step 1
Switch> enable
Step 2
Switch# configure terminal
Step 3
Switch(config)# ip multicast-routing
Step 4
Switch(config)# interface type number
Step 5
Switch(config-if)# ip pim [sparse-mode |
sparse-dense-mode]
Step 6 Repeat Steps 4 and 5 on every interface that uses IP
multicast.
Step 7
Switch(config-if)# exit
Step 8
Switch(config)# ip pim rp-address rp-address
[access-list] [override]
Step 9
Switch(config)# end
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
35-20
Purpose
Enables privileged EXEC mode.
Enters global configuration mode.
Enables IP multicast routing.
Selects an interface that is connected to hosts on which PIM
can be enabled.
Enables PIM on an interface. You must use sparse mode.
—
Returns to global configuration mode.
Configures the address of a PIM RP for a particular group.
• Perform this step on any router.
• The access-list argument specifies the number or name
of an access list that defines for which multicast groups
the RP should be used.
The override keyword specifies that if there is a
•
conflict between the RP configured with this command
and one learned by Auto-RP, the RP configured with
this command prevails.
Ends the current configuration session and returns to EXEC
mode.
Chapter 35 Configuring IP Multicast
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