Specifying the source IP VLAN (optionally configuring multicast groups or range of groups)

Specifying the source IP VLAN ID automatically configures the C-RP to support all multicast groups (unless you include an individual group or range of groups in the command.) The recommended approach is to allow all multicast groups unless you have a reason to limit the permitted groups to a specific set.

Syntax:

[no] rp-candidate source-ip-vlan [vid] [group-prefix group-addr/mask]

[no] router pim rp-candidate source-ip-vlan [vid] [group-prefix group-addr/mask]

These commands configure C-RP operation in the following way:

• Specify the VLAN interface from which the RP IP address will be selected for advertising the router as an RP candidate.

  NOTE:

  Only one VLAN on the router can be configured for this purpose at any time.

• Enable the router as an RP candidate.

• Specify the multicast groups for which the router is a CRP. (Default: Disabled.)

  NOTE:

  When executed without specifying a multicast group or range of groups, the resulting RP candidate defaults to allow support for all valid multicast groups.

Additionally, the following commands may be required:

• To later add to or change multicast groups, or to delete multicast groups, use the command rp-candidate group-prefix [group-addr | group-mask].

• To disable C-RP operation without removing the current CRP configuration, use the command no rp-candidate.

• The no form of these commands:

  • Deletes the RP source IP VLAN configuration.

  • Deletes the multicast group assignments configured on the router for this RP.

  • Disables the router from being an RP candidate.

The <vid> command identifies the VLAN source of the IP address to advertise as the RP candidate address for the router.

The command group-prefix [group-addr/mask] specifies the multicast group(s) to advertise as supported by the RP candidate. Use this option when you want to enable the C-RP and simultaneously configure it to support a subset of multicast addresses or ranges of addresses instead of all possible multicast addresses.

A group prefix can specify all multicast groups (224.0.0.0 to 239.255.255.255), a range (subset) of groups, or a single group. A given address is defined by its nonzero octets and mask. The mask is applied from the high end (leftmost) bits of the address and must extend to the last nonzero bit in the lowest-order, nonzero octet. Any intervening zero or nonzero octet requires eight mask bits. Following are examples.