Citrix SD-WAN Orchestrator


HA near-hitless software upgrade

  1. What are the prerequisites for the HA near-hitless software upgrade?

    The existing customer network must already be running on Citrix SD-WAN 11.1 or higher release which supports the near-hitless upgrade procedure for HA.

  2. Is this functionality enabled by default or is there some setting to enable this?

    It is enabled by default.

  3. What if there are a few sites with Non-HA deployment?

    The sites with non-HA deployment are activated at the second step of activation. If the entire network does not have HA deployment then the single step upgrade is activated.

  4. What if the activation fails either on the Standby or Active appliance?

    The software has a timeout implementation. If the activation on the Standby appliance fails, after the timeout period, activation on the Active appliances is initiated.

  5. How long is the timeout period?

    The timeout periods for various upgrade activations are:

    • Configuration update activation: 5 minutes
    • Near hitless software upgrade for HA Step 1: 20 minutes
    • Near hitless software upgrade for HA Step 2: 20 minutes
    • Single step software upgrade activation: 20 minutes
  6. What if Active and Standby are in different software versions because of error/issues during upgrade?

    The HA pair continues to work in different software versions. Another Change Management Activation is required to bring the HA pair to the same software version.

  7. What if the standby appliance is down when we initiate software upgrade?

    Citrix SD-WAN Orchestrator service cannot complete the first step of near hitless upgrade activation process, which is upgrading the standby appliances and switching the standby appliances to active. It waits for the timeout period to get over and then transitions to the second step. As part of the second step, Citrix SD-WAN Orchestrator service upgrades the active appliances. The standby appliances get upgraded once they come back online.

  8. Can we time schedule software Upgrade/Activation?

    This functionality is not available currently.

  9. Does this process apply to RCN based deployments?


  10. Do we support partial site upgrade?

    Yes. Citrix SD-WAN Orchestrator service supports partial site upgrade from Citrix SD-WAN release 11.2.2 onwards. Even for the partial software upgrade scenarios, HA hitless upgrade is effective.

  11. Do we support revert-on error functionality?

    This functionality is not available currently.

  12. How are non-SD-WAN components such as LTE Firmware, SVM, and Citrix Hypervisor Hotfixes upgraded? Can we have scheduled installation of these non-SD-WAN components?

    This functionality is not available currently.

  13. What if there is any configuration change during the software upgrade? Are we going to inform the user/admin that we are not going to apply the HA near-hitless software upgrade?

    Yes. User/Admin is informed that there is a configuration change during current software upgrade activity. The user is given a choice to continue with the normal single step software upgrade procedure, instead of near-hitless upgrade.