Stateful and Non-Stateful High Availability Prerequisites

–LAN Virtual IP Address – Configured on the X0 interface of the Primary unit. This is the default gateway for all devices configured on the LAN. Accessing the management interface with this IP address will log you into the appliance that is Active whether it is the Primary unit or Backup unit.

–Primary LAN Management IP Address – Configured under High Availability > Monitoring. This is the IP address used for managing the Primary unit over the LAN interface, regardless of the Active or Idle status of the unit.

–Backup LAN Management IP Address – Configured under High Availability > Monitoring. This is the IP address used for managing the Backup unit over the LAN interface, regardless of the Active or Idle status of the unit.

• At least one WAN IP address is required:

–WAN Virtual IP Address – Configured on the X1 Interface of the Primary unit. Accessing the management interface with this IP address will log you into the appliance that is Active whether it is the Primary unit or Backup unit

–Primary WAN Management IP Address (Optional) – Configured under High Availability > Monitoring. This is the IP address used for managing the Primary unit over the WAN interface, regardless of the Active or Idle status of the unit. This requires that you have an additional routable IP address available. This is optional, as you can always manage the Active unit with one static WAN IP address.

–Backup WAN Management IP Address (Optional) – Configured under High Availability > Monitoring. This is the IP address used for managing the Backup unit over the WAN interface, regardless of the Active or Idle status of the unit. This requires that you have an additional routable IP address available. This is optional, as you can always manage the Active unit with one static WAN IP address.

If using only a single WAN IP, note that the Backup device, when in Idle mode, will not be able to use NTP to synchronize its internal clock.

If you will not be using Primary/Backup WAN Management IP address, make sure each entry field is set to ‘0.0.0.0’ (in the High Availability > Monitoring Page) – the SonicWall will report an error if the field is left blank.

If each SonicWall has a Primary/Backup WAN Management IP address for remote management, the WAN IP addresses must be in the same subnet. If shifting a previously assigned interface to act as a unique WAN interface, be sure to remove any custom NAT policies that were associated with that interface before configuring it.

• Register and associate the Primary and Backup SonicWall security appliances as a High Availability pair on MySonicWall, refer the following articles:

– “Associating an Appliance at First Registration” refer Associating an Appliance at First Registration on MySonicWALL for High Availability? 
– “Associating Pre-Registered Appliances” refer How to Associate Pre-Registered Appliances on MySonicWALL for High Availability 
– “Associating a New Unit to a Pre-Registered Appliance” refer Associating a New Unit to a Pre-Registered Appliance on MySonicWall for High Availability
– “Removing an HA Association” refer How to Remove an High Availability (HA) association on the Mysonicwall.com?
– “Replacing a SonicWall Security Appliance” refer How to Replace a Primary or Secondary High Availability (HA) unit?