18
Upgrade/Downgrade Guide, Cisco ACE 4700 Series Application Control Engine Appliance
OL-25719-01
Downgrading Your ACE Software in a Redundant Configuration
Step 2
Configure ACE-1 to automatically boot from the earlier ACE software image. To set the boot variable
and configuration register to 1, use the
boot system image:
and
config-register
commands in
configuration mode. For example, enter:
ACE-1/Admin#
config
ACE-1/Admin(config)#
boot system image:c4710ace-mz.A3_2_7.bin
ACE-1/Admin(config)#
config-register 1
ACE-1/Admin(config)#
exit
ACE-1/Admin#
You can set up to two images through the
boot system
command. If the first image fails, the ACE tries
to boot from the second image.
Note
Use the
no boot system image:
ACE_image
command to remove the configured A3(x.x) boot
variable.
Step 3
Verify that the boot variable was synchronized to ACE-2 by entering the following command on ACE-2:
ACE-2/Admin#
show bootvar
BOOT variable = “disk0:c4710ace-mz.A3_2_7.bin”
Configuration register is 0x1
host1/Admin#
Step 4
Verify the state of each ACE by entering the
show ft group detail
command in Exec mode. Downgrade
first the ACE that has its Admin context in the STANDBY_HOT state (ACE-2) by entering the
reload
command.
ACE-2/Admin#
reload
This command will reboot the system
Save configurations for all the contexts. Save? [yes/no]: [
yes
]
When ACE-2 loads the startup-configuration file, you may observe a few errors if you did not roll back
the configuration to a checkpoint. These errors are harmless and occur because the ACE software does
not recognize the A4(2.0) (or later) commands in the startup-configuration file.
Note
Dynamic incremental sync is automatically disabled while the active ACE is running software
version A4(2.0) or later and the standby ACE is running an earlier software version.
Step 5
Perform a graceful failover of all contexts from ACE-1 to ACE-2 by entering the
ft switchover all
command in Exec mode on ACE-1. ACE-2 becomes the new active ACE and assumes control of all
active connections with no interruption to existing connections.
ACE-1/Admin#
ft switchover all
Step 6
Reload ACE-1 with the same ACE software version as ACE-2. You may observe a few errors as ACE-1
loads the startup-configuration file.
ACE-1/Admin#
reload
After ACE-1 boots up, it assumes the role of standby and enters the STANDBY_HOT state (this can take
several minutes). You can verify the states of both ACEs by entering the
show ft group detail
command
in Exec mode. Because the standby ACE has changed its state to either STANDBY_COLD or
STANDBY_HOT, the configuration mode is enabled. The configuration is synchronized from ACE 2
(currently active) to ACE-1. If ACE-1 is configured with a higher priority and
preempt
is configured on
the FT group, ACE-1 reasserts control after it has received all configuration and state information from
ACE-2, making ACE-2 the new standby. ACE-1 becomes the active ACE again.
