The c-bsr global command configures the switch as a C-BSR in the global domain.
The undo c-bsr global command restores the default configuration.
By default, no C-BSR is configured in the global domain.
| Parameter | Description | Value |
|---|---|---|
hash-length hash-length |
Specifies the hash mask length of a C-BSR in the global domain. |
The value is an integer that ranging from 0 to 32. By default, the value is 30. |
priority priority |
Specifies the priority of the C-BSR in the global domain. The greater the value, the higher the priority of the C-BSR. |
The value is an integer ranging from 0 to 255. By default, it is 0. |
Usage Scenario
By default, each PIM-SM domain has only one BootStrap router (BSR) and the BSR serves all the devices in the entire PIM-SM domain. To achieve more effective management, you can divide a PIM-SM domain into multiple BSR administrative domains and a global domain.
Each BSR administrative domain maintains one BSR that serves the multicast groups in a specific group address range. Multicast packets for groups in the range cannot pass through the border of the BSR administrative domain. Addresses of multicast groups that BSRs in different BSR administrative domains serve can overlap. Overlapped multicast groups, however, similar to private group addresses, take effect only in local BSR administrative domains. Multicast groups that do not belong to any BSR administrative domain belong to a global domain. A global domain maintains a BSR that serves all the remained multicast groups.
The c-bsr global command configures the switch as a C-BSR in the global domain. The BSR in the global domain is generated through election.
C-BSRs compare the priorities and IP addresses to elect the BSR in the global area. The conditions for the election are as follows:
The C-BSR with the highest priority is elected as the BSR.
In the case of the same priority, the C-BSR with the largest IP address is elected as the BSR.
Prerequisites
IP multicast routing has been enabled using the multicast routing-enable command.
Configuration Impact
If the c-bsr global command is run several times, the latest configuration overrides the previous one.
After the undo pim command or the undo multicast routing-enable command is run in the system view, the C-BSRs in the global domain are automatically disabled.
Precautions
The c-bsr global command takes effect only in a BSR administrative domain and can enable a device in a BSR administrative domain to receive multicast data of groups beyond 239.0.0.0/8.
The c-bsr global command needs to be used together with the c-bsr admin-scope command.