6-12
Software Configuration Guide—Release 12.2(25)SG
OL-7659-03
Chapter 6 Configuring Supervisor Engine Redundancy Using RPR and SSO
Performing a Software Upgrade
To perform a manual switchover, perform this task on the active supervisor engine:
Be aware of these usage guidelines:
• To force a switchover, the redundant supervisor engine must be in a standby hot state. You can verify
the state with the show redundancy command. If the state is not standby hot, the
redundancy force-switchover command will not execute.
• Use the redundancy force-switchover command, rather than the reload command, to initiate a
switchover. The redundancy force-switchover command will first check that the redundant
supervisor engine is in the correct state. If you issue the reload command and the status is not
standby hot, the reload command will reset the current supervisor engine only.
After an initial switchover, there might be occasions when you want to make the supervisor engine in
slot 1 of the chassis the active supervisor engine. If the image on supervisor engine 1 is the one you
intend to run on both supervisor engines, it is not necessary to re-boot the image on the supervisor engine
in slot 1 to make it redundant. Instead, you can force another switchover. However, if you want a newer
version of the image to run on both supervisor engines, follow the steps under “Performing a Software
Upgrade” on page 12. Use the show module command to see which slot contains the active supervisor
engine, and force another switchover if necessary.
Performing a Software Upgrade
The software upgrade procedure supported by supervisor engine redundancy allows you to reload the
Cisco IOS software image on the redundant supervisor engine, and once complete, reload the active
supervisor engine once.
If the active supervisor engine is running IOS Release 12.2(x)S, the standby supervisor engine cannot
run IOS Release 12.1(x)E. This would reset the switch immediately after the system boot of the standby
supervisor engine. The reverse configuration, where the standby engine is running IOS Release 12.2(x)S
and the active supervisor engine is running 12.1(x)E, is fully supported.
Command Purpose
Step 1
Switch# show redundancy
Verifies that the peer state is in the STANDBY HOT
state.
See the example of the show redundancy states
command on page 6-10.
Step 2
Switch# redundancy force-switchover
Launches switchover from the active supervisor engine
to the redundant supervisor engine.
If the state of the redundant supervisor engine is not
standby hot, this command will not execute.
