Crp-Policy - 3Com 8807 Command Reference Manual

620 C 36: PIM C C
HAPTER ONFIGURATION OMMANDS
[3Com-acl-basic-2000] rule permit source 225.0.0.0 0.255.255.255
[3Com-acl-basic-2000]quit
[SW8800] multicast routing-enable
[SW8800] pim
[3Com-pim] c-rp vlan-interface 10 group-policy 2000

crp-policy

Syntax
crp-policy acl-number
undo crp-policy
View
PIM view
Parameter
acl-number: ACL number imported in C-RP filtering policy, ranging from 3000 to
3999.
Description
Use the crp-policy command to limit the range of legal C-RP, as well as target
service group range of each C-RP, and prevent C-RP proofing.
Use the undo crp-policy command to restore the default setting, that is, no
range limit is set and all received messages are taken as legal.
In the PIM SM network using BSR mechanism, every router can set itself as C-RP
(candidate rendezvous point) servicing particular groups. If elected, a C-RP
becomes the RP servicing the current group.
In BSR mechanism, a C-RP router unicasts C-RP messages to the BSR, which then
propagates the C-RP messages among the network by BSR message.
To prevent C-RP spoofing, you need to configure crp-policy on the BSR to limit
legal C-RP range and their service group range. Since each C-BSR has the chance
to become BSR, you must configure the same filtering policy on each C-BSR
router.
This command uses the ACLs numbered between 3000 and 3999. The source
parameter in the rule command is translated as C-RP address in the crp-policy
command, and the destination parameter as the service group range of this C-RP
address. For the C-RP messages received, only when their C-RP addresses match
the source address and their server group addresses are subset of those in ACL,
can the be considered as matched.
Related command: acl and rule.
Example
# Configure C-RP filtering policy on the C-BSR routers, allowing only 1.1.1.1/32 as
C-RP and to serve only for the groups 225.1.0.0/16.
<SW8800> system-view
System View: return to User View with Ctrl+Z.
[SW8800] multicast routing-enable
[SW8800] pim