Manually Switching Routing Engine Mastership

Action

To manually switch the Routing Engine mastership, use one of the following CLI commands.

• From the backup Routing Engine, request the backup Routing Engine to acquire mastership:

user@host> request chassis routing-engine master acquire

user@host> request chassis routing-engine master acquire

warning: Traffic will be interrupted while the PFE is re-initialized

Attempt to become the master routing engine ? [yes,no] (no)

Resolving mastership...

Complete. The local routing engine becomes the master.

• From the master Routing Engine, request the backup Routing Engine to acquire mastership:

user@host> request chassis routing-engine master release

user@host> request chassis routing-engine master release

Traffic will be interrupted while the PFE is re-initialized

Request the other routing engine become master ? [yes,no] (no) 

Resolving mastership...

Complete. The other routing engine becomes the master.

• Switch mastership from either the backup or master Routing Engine:

user@host> request chassis routing-engine master switch

If graceful-switchover is not configured, the command output looks as follows:

user@host> request chassis routing-engine master switch

warning: Traffic will be interrupted while the PFE is re-initialized

Toggle mastership between routing engines ? [yes,no] (no) yes 

Resolving mastership...

Complete. The local routing engine becomes the master.

user@host> request chassis routing-engine master switch

If graceful-switchover is configured the command output looks as follows:

Toggle mastership between routing engines ? [yes,no] (no) yes 

Resolving mastership...

Complete. The other routing engine becomes the master.

What It Means

When you enter the request chassis routing-engine master acquire command on the backup Routing Engine, you see the following:

warning: Traffic will be interrupted while the PFE is re-initialized

Attempt to become the master routing engine ? [yes,no] (no). 

The master Routing Engine gives up control of the system bus and goes into the backup state. The backup Routing Engine becomes master and restarts the Packet Forwarding Engine. You can then diagnose the original master Routing Engine for problems or prepare it for upgrade or reconfiguration. When switchover occurs, the backup Routing Engine does not run through its full boot cycle (only the packet forwarding components run through a full boot cycle).

When you enter the request chassis routing-engine master release command on the master Routing Engine, the system passes mastership to the backup Routing Engine. The master Routing Engine gives up control of the system bus and goes into the backup state. The backup Routing Engine becomes master and restarts the Packet Forwarding Engine. You can then diagnose the original master Routing Engine for problems or prepare it for upgrade or reconfiguration.

In all cases, once the switchover occurs, the new master Routing Engine reestablishes routing adjacencies, populates the routing table, and transfers forwarding table information to the Packet Forwarding Engine. When Routing Engine mastership changes, the Packet Forwarding Engine components are rebooted to reestablish communication links and download the microkernel to each component. When this occurs, forwarding is interrupted and packet buffers are flushed.