Brocade Communications Systems IPMC5000PEF manual Configuring RPs

Configuring RPs

The numhash-mask-lengthvariable specifies the number of bits in a group address that are significant when calculating the group-to-RP mapping. You can specify a value from 1 to 32.

NOTE

it is recommended that you specify 30 for IP version 4 (IPv4) networks.

The priority variable specifies the BSR priority. You can specify a value from 0 to 255. When the election process for BSR takes place, the candidate BSR with the highest priority becomes the BSR. The default is 0.

Configuring RPs

Enter a command such as the following to configure the device as a candidate RP.

device(config-pim-router)# rp-candidate ethernet 2/2

Syntax: [no] rp-candidate ethernet slot / portnum loopback num ve num

The ethernetslot /portnum loopbacknum venum parameters specify the interface. The device will advertise the IP address of the specified interface as a candidate RP.

•Enter ethernetslot /portnum for a physical interface (port).

•Enter venum for a virtual interface.

•Enter loopbacknum for a loopback interface.

By default, this command configures the device as a candidate RP for all group numbers beginning with

224.As a result, the device is a candidate RP for all valid PIM Sparse group numbers. You can change this by adding or deleting specific address ranges. Consider the following when configuring the RP.

•When the candidate RP is configured, before explicitly specifying the groups that it serves, the c-rp does, by default, serve all the groups in the PIMSM multicast range, but this includes all groups beginning with 224.x.x.x all the way up to 239.x.x.x. This is reflected in the "rp-candidate add 224.0.0.0 4" line displayed as part of the runtime configs. This entry will be referred to as the

DEFAULT PREFIX.

•When any group prefix is explicitly added (and the 224.0.0.0/4 prefix itself can also be explicitly added through CLI), the default prefix is implicitly removed. Now, the only groups served by the candidate RP, are the groups that have been explicitly added.

•All explicitly added groups can be removed using the "delete" option or "no ... add" option. However, once all the explicitly added groups are deleted from the Candidate RP group prefix list, the default prefix becomes active once more. This default group prefix CANNOT BE REMOVED.

•It is not possible to punch holes in the group prefix range. For instance executing

rp-candidate add 228.0.0.0/16

and then,

rp-candidate delete 228.0.1.0/24

is not permissible. It cannot be used to ensure that the rp-candidate will serve all group prefixes in the 228.0.0.0/16 range except those in the 228.0.1.0/24 range.

The following example narrows the group number range for which the device is a candidate RP by explicitly adding a range.

device(config-pim-router)# rp-candidate add 224.126.0.0 16

Syntax: [no] rp-candidate add group-addrmask-bits

The group-addrmask-bitsspecifies the group address and the number of significant bits in the subnet mask. In this example, the device is a candidate RP for all groups that begin with 224.126. When you

FastIron Ethernet Switch IP Multicast Configuration Guide	99
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