The c-bsr command configures a C-BSR.
The undo c-bsr command restores the default configuration.
By default, the C-BSR is not configured.
| Parameter | Description | Value |
|---|---|---|
| interface-type interface-number | Specifies the type and the number of an interface. C-BSR
is configured on this interface. PIM-SM must be enabled on this interface
to make the configuration effective. NOTE:
To avoid frequent protocol changes caused by interface flapping, using loopback interfaces is recommended. |
- |
| hash-length | Specifies the hash mask length of the C-BSR. The mask is used in a hash function to calculate the RP. | The value is an integer that ranges from 0 to 32. By default, the value is 30. |
| priority | Specifies a priority of the C-BSR. The greater the value, the higher the priority of the C-BSR. | The value is an integer ranging from 0 to 255. By default, the value is 0. |
Usage Scenario
One or more C-BSRs need to be configured in a PIM-SM domain. A BSR is elected from C-BSRs and is responsible for collecting C-RP information and summarizing C-RP information into an RP-set. The RP-set is then encapsulated in a BootStrap message and advertised to all the devices in the PIM domain.
The process of BSR election is as follows:
Each C-BSR considers itself as the BSR of the local PIM-SM domain and uses IP address of this interface as the address of the BSR to send Bootstrap messages.
When a C-BSR receives a Bootstrap message from other devices, it compares the BSR in the received Bootstrap message with the current BSR. The BSR with the highest priority is preferred. If BSRs have the same priority, the BSR with a larger IP address is preferred. If the BSR carried in the received Bootstrap message is superior to the current BSR, the C-BSR replaces its BSR address with the address of the BSR carried in the received Bootstrap message.
Prerequisites
IP multicast routing has been enabled using the multicast routing-enable command.
Before configuring an interface as a C-BSR, enable PIM-SM on the interface.
For the multicast BSR messages learned through the GRE tunnel, you need to configure a static multicast route to ensure that the next hop to the BSR is a GRE interface. You need to configure static multicast routes properly to avoid routing loops.
<HUAWEI> system-view [HUAWEI] multicast routing-enable [HUAWEI] interface vlanif 100 [HUAWEI-Vlanif100] pim sm [HUAWEI-Vlanif100] quit [HUAWEI] pim [HUAWEI-pim] c-bsr vlanif 100
<HUAWEI> system-view [HUAWEI] multicast routing-enable [HUAWEI] interface gigabitethernet 0/0/1 [HUAWEI-GigabitEthernet0/0/1] undo portswitch [HUAWEI-GigabitEthernet0/0/1] pim sm [HUAWEI-GigabitEthernet0/0/1] quit [HUAWEI] pim [HUAWEI-pim] c-bsr gigabitethernet 0/0/1