H3C Technologies H3C SR6600 - Manual (Page 74)

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Active and standby switchover for MPUs
CAUTION:
•
Do not execute any command on the standby MPU.
• Do not use the H3C SR6602-specific software to upgrade the H3C SR6604/6608 routers. Otherwise,
the system will fail.
A router can be configured with two MPUs of the same model, one acting as the active MPU and the
other as the standby MPU. When RPE-X1 MPUs are used, the MPU in slot 0 is the active MPU by default.
When RSE-X1 MPUs are used, the MPU in slot 1 is the active MPU by default. When the MCP-X1 or
MCP-X2 MPUs are used, the MPU in slot 1 is the active MPU by default. The standby MPU uses the
synchronization function to keep its configuration consistent with the current configuration of the active
MPU. When the active MPU fails, the standby MPU immediately takes over using the same configuration
as the previous active MPU, and guarantees that the router operates correctly. The process is called an
active and standby switchover.
An active and standby switchover is triggered in the following conditions:
• The active MPU fails.
• The active MPU is unplugged.
• Remotely performing an active and standby switchover through SNMP.
• Manually executing the command for active and standby switchover.
Active/standby switchover is implemented in the following workflow:
1. The standby MPU automatically connects to and controls the system bus, and at the same time, the
former active MPU disconnects from the system bus.
2. The standby MPU becomes an active MPU, and the former active MPU automatically reboots and
becomes a standby MPU.
When the standby MPU is started, the active MPU performs initial synchronization for the standby MPU.
During the synchronization process, if you press Enter on the configuration terminal, the system prompts
that you cannot execute any command on the active MPU or standby MPU. After the initial
synchronization process is complete, you can execute configuration commands on the active MPU, and
the configurations of the active MPU are real-time synchronized (copied) to the standby MPU, so that the
active MPU and the standby MPU can have the same configurations.
You can use the slave switchover command to trigger an active and standby switchover. For more
information about the command, see H3C SR6600/SR6600-X Routers High Availability Command
Reference.
Solving system faults
Solving system faults
When the system detects faults (such as system instruction faults, invalid addresses, data overflow, null
pointers, and division by zero operations) during the operation of the active MPU or standby MPU, you
can solve the problem in one of the following methods:
• reboot—Rebooting the failed MPU so that the MPU restores to normal operational status.