3Com Switch 8800 Advanced Software V5 Configuration Guide

Configuring PIM-SM 583
Configuring a C-RP
In a PIM-SM domain, you can configure devices that intend to become the RP into
C-RPs. The BSR collects the C-RP information by receiving the C-RP-Adv messages
from C-RPs or auto-RP announcements from other devices and organizes the
information into to an RP-Set, which is flooded throughout the entire network.
Then, the other devices in the network calculate the mappings between specific
group ranges and the corresponding RPs based on the RP-Set. We recommend
that you configure C-RPs on backbone devices.
To guard again C-RP spoofing, you need to configure a legal C-RP address range
and the range of multicast groups to be served on the BSR. In addition, because
every C-BSR has a chance to become the BSR, you need to configure the same
filtering policy on all C-BSRs.
Follow these steps to configure a C-RP:
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■ When configuring a C-RP, ensure a relatively large bandwidth between this
C-RP and the other devices in the PIM-SM domain.
■ An RP can serve multiple multicast groups or all multicast groups. Only one RP
can forward multicast traffic for a multicast group at a moment.
Enabling auto-RP
Auto-RP announcement and discovery messages are respectively addressed to the
multicast group addresses 224.0.1.39 and 224.0.1.40. With auto-RP enabled on a
device, the device can receive these two types of messages and record the RP
information carried in such messages.
Follow these steps to enable auto-RP:
To do... Use the command... Remarks
Enter system view system-view -
Enter PIM view pim -
Configure a static RP static-rp rp-address [
acl-number ] [ preferred ]
Optional
No static RP by default
To do... Use the command... Remarks
Enter system view system-view -
Enter PIM view pim -
Configure an interface to be a
C-RP
c-rp interface-type
interface-number [
group-policy acl-number |
priority priority | holdtime
hold-interval |
advertisement-interval
adv-interval ] *
Optional
No C-RPs are configured by
default
Configure a legal C-RP
address range and the range
of multicast groups to be
served
crp-policy acl-number Optional
No restrictions by default