c-bsr holdtime (IPv4)

Function

The c-bsr holdtime command configures the timeout period during which the C-BSR waits to receive Bootstrap messages sent by the BSR.

The undo c-bsr holdtime command restores the default configuration.

By default, the timeout period during which the C-BSR waits to receive Bootstrap messages sent by the BSR is 130s.

Format

c-bsr holdtime interval

undo c-bsr holdtime

Parameters

Parameter	Description	Value
interval	Specifies the timeout time during which C-BSR waits for the Bootstrap message to be sent by BSR.	The value is an integer that ranges from 1 to 214748364, in seconds.

Views

PIM view of public network instance or PIM view of VPN instance

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

After a C-BSR is elected as the BSR, it periodically sends Bootstrap messages carrying its own IP address and the RP-set information. The interval for sending Bootstrap messages is BS_interval, which can be configured using the c-bsr interval command.

Other C-BSRs that fail in the election are suppressed from sending Bootstrap messages and start the timer to monitor the elected BSR. The timeout period of a timer is holdtime, which can be configured using the c-bsr holdtime command.

If the C-BSR receives the Bootstrap messages sent by the BSR, the C-BSR refreshes the timer. The C-BSRs that fail in the election also refresh the timeout period of the BSR according to the holdtime. After the BSR times out, the C-BSRs receive new BSR messages.
If the timer times out, the elected BSR is considered faulty. The C-BSRs that failed in the election triggers a new BSR election, preventing service interruption.

Prerequisites

IP multicast routing has been enabled using the multicast routing-enable command.

Precautions

In actual applications, all C-BSRs in the same PIM domain must use the same BS_interval and holdtime; otherwise, the BSR will become unstable. This may result in multicast faults. Note the following points:

If BS_interval and holdtime are configured at the same time, ensure that BS_interval is less than holdtime.
If BS_interval or holdtime is configured, use the following formula to calculate the other one: holdtime = 2 x BS_interval + 10. The following determines which value is used:
- If holdtime is configured and the calculated BS_interval is less than the minimum value of BS_interval, the minimum value is used.
- If BS_interval is configured and the calculated holdtime is more than the maximum value of holdtime, the maximum value is used.
If neither BS_interval nor holdtime is configured, the default values are used. The default BS_interval is 60s and the default holdtime is 130s.

Example

# In the PIM view of public network instance, set the timeout interval during which the C-BSR waits for the Bootstrap message to be sent by BSR to 150 seconds.

<HUAWEI> system-view
[HUAWEI] multicast routing-enable
[HUAWEI] pim
[HUAWEI-pim] c-bsr holdtime 150