Citrix SD-WAN

Managing licenses

Citrix SD-WAN appliances licenses are managed by communicating with the remote license service to check for licenses. If the appliance is licensed, the network operations continue without interruption. If the appliance is not licensed, the grace license mode is initiated.

SD-WAN appliance license management process:

  1. Each site communicates with Remote Server or SD-WAN Center using the Web Management Interface. This communication occurs through a heartbeat mechanism to monitor connectivity and a checkout mechanism that verifies the license status.

  2. Heartbeats are sent over a TCP connection to the license server every 10–20 mins to check connectivity.

  3. After a loss of two consecutive Heartbeats, the appliance goes into a grace mode. The checkout method determines the license status. This status could be “Real,” “Grace,” or “Denied” that is sent to the appliance from the SD-WAN Center. Every time an appliance reaches out to the SD-WAN Center for license status, it checks-in and checks-out the new license. If SD-WAN center does not receive two heart beats, the SD-WAN center releases the license allocated to the site into the pool. The grace period is 30 days, so after loss of 2 heartbeats, the appliance goes into the grace period. During these 30 days, the communication has to be restored. Once restored, the appliance reverts to normal operational mode. If the communication is NOT restored, the appliance is put into unlicensed state and follows the unlicensed/license expiry procedure.

Out-of-Box licensing (OOB) for MCN appliance:

  • MCN appliance will not have an initial grace period. It needs to be licensed to come up.

Out-of-Box licensing (OOB) for client appliance:

  • Client node comes up with a 30-day grace period with or without ZTD functionality.
  • The appliance is enabled with a OOB license file valid for 30 days.
  • You have 30 days to upload a license file or get licensed through the Centralized Licensing server.
  • If the appliance is licensed, it functions normally and be part of the network.
  • If the appliance is not licensed within 30 days, the license expiry procedure is followed.

The only way to reset the appliance to again come up with OOB license is to perform a “Factory Reset.”

Managing licenses

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