• SonicOS 7.1
• About SonicOS
  • Working with SonicOS
  • SonicOS Workflow
  • How to Use the SonicOS Administration Guides
  • Guide Conventions
• High Availability
  • About High Availability
    • High Availability Terminology
    • High Availability Modes
    • High Availability Encryption
    • Crash Detection
    • Virtual MAC Address
    • Dynamic WAN Interfaces with PPPoE HA
    • Stateful Synchronization with DHCP
    • Stateful Synchronization with DNS Proxy
    • About HA Monitoring
  • About Active/Standby HA
    • Benefits of Active/Standby HA
    • Working of Active/Standby HA
  • About Stateful Synchronization
    • Benefits of Stateful Synchronization
    • How Does Stateful Synchronization Work?
    • Example of Stateful Synchronization
  • Active/Standby Prerequisites
    • Supported Platforms and Licensing for HA
    • Physically Connecting Your Security Appliances
  • Maintenance
    • Removing an HA Association
    • Replacing a SonicWall Security Appliance
      • Replacing an HA Primary Unit
      • Replacing an HA Secondary Unit
• High Availability Status
  • Active/Standby High Availability Status
    • High Availability Status
    • High Availability Config
    • High Availability Licenses
• Configuring High Availability
  • Configuring Active/Standby High Availability Settings
  • Configuring HA with Dynamic WAN Interfaces
• Configuring High Availability in the Cloud Platform
  • Set up an Active/Standby High Availability Configuration Using Azure
    • Install the Custom Template
    • Enable Identity of Both Virtual Machines (HA1 and HA2)
    • Role Assignment
    • Check the Networking Tab
    • Configuring Active NSv Firewall Using the Associated Public IP
    • Configuring Standby NSv Firewall Using the Associated Public IP
    • Enable the L3 Mode
    • Configuring Active NSv Firewall Using the Floating Public IP
    • Configuring HA to Active/Standby with L3 HA link
    • Adding Additional Floating Public IP
• Fine Tuning High Availability
  • Advanced Settings
  • Configuring Advanced High Availability Settings
• Monitoring High Availability
  • Configuring Active/Standby High Availability Monitoring
  • IPv6 High Availability Monitoring
  • IPv6 HA Monitoring Considerations
• Azure Use Cases
  • Use Case 1: Manage Azure HA Firewall
  • Use Case 2: Forward LAN traffic to the External Network through the Gateway after HA Failover
  • Use Case 3: Configure DNAT on Azure HA Firewall
  • Use Case 4: Configure DNAT on Azure HA Firewall (Need to move multiple floating IPs support)
• SonicWall Support
  • About This Document

High Availability Modes

High Availability has several operation modes, which can be selected on DEVICE | High Availability > Settings.

• None - Selecting None activates a standard high availability configuration and hardware failover functionality, with the option of enabling Stateful HA.

• Active/Standby - Active/Standby mode provides basic high availability with the configuration of two identical Security Appliances as a High Availability Pair. The Active unit handles all traffic, while the Standby unit shares its configuration settings and can take over at any time to provide continuous network connectivity if the Active unit stops working.

  By default, Active/Standby mode is stateless, meaning that network connections and VPN tunnels must be re-established after a failover. To avoid this, Stateful Synchronization can be licensed and enabled with Active/Standby mode. In this Stateful HA mode, the dynamic state is continuously synchronized between the Active and Standby units. When the Active unit encounters a fault condition, stateful failover occurs as the Standby Security Appliance takes over the Active role with no interruptions to the existing network connections.

• Active/Active DPI—The Active/Active Deep Packet Inspection (DPI) mode can be used along with the Active/Standby mode. When Active/Active DPI mode is enabled, the processor intensive DPI services, such as Intrusion Prevention (IPS), Gateway Anti-Virus (GAV), and Anti-Spyware are processed on the standby Security Appliance, while other services, such as firewall, NAT, and other types of traffic are processed on the Active Security Appliance concurrently.

  Active/Active DPI is:

  For licensing information, see SonicOS 7.1 Settings document.

• Active/Active Clustering—In this mode, multiple Security Appliances are grouped together as cluster nodes, with multiple Active units processing traffic (as multiple gateways), doing DPI and sharing the network load. Each cluster node consists of two units acting as a Stateful HA pair. Active/Active Clustering provides Stateful Failover support in addition to load-sharing. Optionally, each cluster node can also consist of a single unit, in which case Stateful Failover and Active/Active DPI are not available.

  Active/Active Clustering is:

  For licensing information, see SonicOS 7.1 Settings document.

• Active/Active DPI Clustering—This mode allows for the configuration of up to four HA cluster nodes for failover and load sharing, where the nodes load balance the application of DPI security services to network traffic. This mode can be enabled for additional performance gain, utilizing the standby units in each cluster node.

  Active/Active DPI Clustering is:

  For licensing information, see SonicOS 7.1 Settings document.