Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/​go/​cfn. An account on Cisco.com is not required.

Auto-RP automates the distribution of group-to-rendezvous point (RP) mappings in a PIM network. To make Auto-RP work, a device must be designated as an RP mapping agent, which receives the RP announcement messages from the RPs and arbitrates conflicts. The RP mapping agent then sends the consistent group-to-RP mappings to all other devices by way of dense mode flooding.

Thus, all routers automatically discover which RP to use for the groups they support. The Internet Assigned Numbers Authority (IANA) has assigned two group addresses, 224.0.1.39 and 224.0.1.40, for Auto-RP.

The mapping agent receives announcements of intention to become the RP from Candidate-RPs. The mapping agent then announces the winner of the RP election. This announcement is made independently of the decisions by the other mapping agents.

As shown in the figure, address scoping defines domain boundaries so that domains with RPs that have the same IP address do not leak into each other. Scoping is performed on the subnet boundaries within large domains and on the boundaries between the domain and the Internet.

Figure 1. Address Scoping at Boundaries

You can set up an administratively scoped boundary on an interface for multicast group addresses using the ip multicast boundary command with the access-list argument. A standard access list defines the range of addresses affected. When a boundary is set up, no multicast data packets are allowed to flow across the boundary from either direction. The boundary allows the same multicast group address to be reused in different administrative domains.

The Internet Assigned Numbers Authority (IANA) has designated the multicast address range 239.0.0.0 to 239.255.255.255 as the administratively scoped addresses. This range of addresses can be reused in domains administered by different organizations. They would be considered local, not globally unique.

You can configure the filter-autorp keyword to examine and filter AutoRP discovery and announcement messages at the administratively scoped boundary. Any AutoRP group range announcements from the AutoRP packets that are denied by the boundary access control list (ACL) are removed. An AutoRP group range announcement is permitted and passed by the boundary only if all addresses in the AutoRP group range are permitted by the boundary ACL. If any address is not permitted, the entire group range is filtered and removed from the AutoRP message before the AutoRP message is forwarded.

• Auto-RP allows any change to the RP designation to be configured only on the devices that are RPs, not on the leaf routers.

• Auto-RP offers the ability to scope the RP address within a domain.

Before You Begin

• An interface configured in sparse-dense mode is treated in either sparse mode or dense mode of operation, depending on the mode in which the multicast group operates. You must decide how to configure your interfaces.

• All access lists that are needed when Auto-RP is configured should be configured prior to beginning the configuration task.

Note

If a group has no known RP and the interface is configured to be sparse-dense mode, the interface is treated as if it were in dense mode, and data is flooded over the interface. To avoid this data flooding, configure the Auto-RP listener and then configure the interface as sparse mode. When configuring Auto-RP, you must either configure the Auto-RP listener feature (Step 5) and specify sparse mode (Step 7) or specify sparse-dense mode (Step 8) . When you configure sparse-dense mode, dense mode failover may result in a network dense-mode flood. To avoid this condition, use PIM sparse mode with the Auto-RP listener feature.

Follow this procedure to configure auto-rendezvous point (Auto-RP). Auto-RP can also be optionally used with anycast RP.

1.    enable


2.    configure terminal


3.    ip multicast-routing [distributed]


4.    Either perform Steps 5 through 7 or perform Steps 6 and 8.

5.    ip pim autorp listener


6.    interface type number


7.    ip pim sparse-mode


8.    ip pim sparse-dense-mode


9.    exit


10.    Repeat Steps 1 through 9 on all PIM interfaces.

11.    ip pim send-rp-announce {interface-type interface-number | ip-address} scope ttl-value [group-list access-list] [interval seconds] [bidir]


12.    ip pim send-rp-discovery [interface-type interface-number] scope ttl-value [interval seconds]


13.    ip pim rp-announce-filter rp-list access-list group-list access-list


14.    no ip pim dm-fallback


15.    interface type number


16.    ip multicast boundary access-list [filter-autorp]


17.    end


18.    show ip pim autorp


19.    show ip pim rp [mapping] [rp-address]


20.    show ip igmp groups [group-name | group-address| interface-type interface-number] [detail]


21.    show ip mroute [group-address | group-name] [source-address | source-name] [interface-type interface-number] [summary] [count] [active kbps]

> enable

# configure terminal

(config)# ip multicast-routing

(config)# ip pim autorp listener

(config)# interface Gigabitethernet 1/0/0

(config-if)# ip pim sparse-mode

(config-if)# ip pim sparse-dense-mode

(config-if)# exit

(config)# ip pim send-rp-announce loopback0 scope 31 group-list 5 

(config)# ip pim send-rp-discovery loopback 1 scope 31 

(config)# ip pim rp-announce-filter rp-list 1 group-list 2

(config)# no ip pim dm-fallback

(config)# interface gigabitethernet 1/0/0

(config-if)# ip multicast boundary 10 filter-autorp

(config-if)# end

# show ip pim autorp

# show ip pim rp mapping

# show ip igmp groups

# show ip mroute cbone-audio