This article describes how a software update of the firmware and the ASDM can be carried out on an active Cisco ASA firewall cluster. With this method, no interruption of the actual operation of the firewall is required. The following 6 steps are necessary for the update.

Upload of the firmware and the ASDM software to the primary cluster unit
  • The following steps upload the firmware and ASDM software to the Primary Cluster Unit. I only describe the procedure for the command line. It is assumed that the administrator has already authenticated himself using ssh and has switched to privileged mode. Uploading the firmware and ASDM software via the command line using a TFTP server is done with the following command.
    copy tftp://"IP-TFTP-Server"/"Path from TFTP-Root"/"Filename" flash:/"Filename"
Name the firmware and ASDM software to be used after a reload

The next lines name the command lines that define which firmware and ASDM software is to be used after a reload. Note: The configuration only has to be done via the Primary Cluster Unit. This is because every configuration change is automatically transferred to the Standby Cluster Unit. 

  • Configuring the boot image via CLI and saving the configuration change
    conf t
    boot system disk0:/„asa-firmware“.bin
    asdm image disk0:/„asdm-software“.bin
    end
    write memory
Verify that we are on the currently active cluster unit via terminal

Now we have to check that we are only logged in to the active cluster unit via the terminal. Note: Before we proceed further, we have to make sure that the configuration is saved on both cluster units.

  • he command for the status check is:
    show failover state
Restarting the previous standby unit
  • Restart the standby cluster unit using the command:
    failover reload-standby
Role change of the active cluster unit

Note: The following step can only be carried out when the standby unit is ready for operation again and the configuration has been synchronised accordingly by the primary unit. 

  • The role of the active (cluster unit) is ceded to the previous standby unit:
    no failover active
Restart of the 2nd cluster unit
  • Attention: The previous management IP addresses have changed as a result of the previous command. Now I check that I am logged in to the active cluster unit via terminal and reload the now new standby cluster unit with the following commands:
    show failover state
    failover reload-standby
  • Note: The following step can only be performed when the primary unit is ready for operation again and the configuration has been replicated accordingly from the standby unit. The role of the active (cluster unit) is returned to the primary unit.
    no failover active

    Attention: The management IP addresses were changed again by the previous command.