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Catalyst 3750 SwitchSoftware Configuration Guide
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Chapter46 Configuring IP Multicast Routing
Configuring IP Multicast Routing
To remove an RP address, use the no ip pim rp-address ip-address [access-list-number] [override]
global configuration command.
This example shows how to configure the address of the RP to 147.106.6.22 for multicast
group 225.2.2.2 only:
Switch(config)# access-list 1 permit 225.2.2.2 0.0.0.0
Switch(config)# ip pim rp-address 147.106.6.22 1
Configuring Auto-RP
Auto-RP uses IP multicast to automate the distribution of group-to-RP mappings to all Cisco routers and
multilayer switches in a PIM network. It has these benefits:
•It is easy to use multiple RPs within a network to serve different group ranges.
•It provides load splitting among different RPs and arrangement of RPs according to the location of
group participants.
•It avoids inconsistent, manual RP configurations on every router and multilayer switch in a PIM
network, which can cause connectivity problems.
Follow these guidelines when configuring Auto-RP:
•If you configure PIM in sparse mode or sparse-dense mode and do not configure Auto-RP, you must
manually configure an RP as described in the “Manually Assigning an RP to Multicast Groups”
section on page 46-24.
•If routed interfaces are configured in sparse mode, Auto-RP can still be used if all devices are
configured with a manual RP address for the Auto-RP groups.
•If routed interfaces are configured in sparse mode and you enter the ip pim autorp listener global
configuration command, Auto-RP can still be used even if all devices are not configured with a
manual RP address for the Auto-RP groups.
These sections describe how to configure Auto-RP:
•Setting up Auto-RP in a New Internetwork, page46-26 (optional)
•Adding Auto-RP to an Existing Sparse-Mode Cloud, page46-26 (optional)
•Preventing Join Messages to False RPs, page46-28 (optional)
•Filtering Incoming RP Announcement Messages, page46-29 (optional)
For overview information, see the “Auto-RP” section on page46-6.

Setting up Auto-RP in a New Internetwork

If you are setting up Auto-RP in a new internetwork, you do not need a default RP because you configure
all the interfaces for sparse-dense mode. Follow the process described in the “Adding Auto-RP to an
Existing Sparse-Mode Cloud” section on page46-26. However, omit Step 3 if you want to configure a
PIM router as the RP for the local group.

Adding Auto-RP to an Existing Sparse-Mode Cloud

This section contains some suggestions for the initial deployment of Auto-RP into an existing
sparse-mode cloud to minimize disruption of the existing multicast infrastructure.