Firewall SonicWall TZ380 High Availability — SonicWall TZ380 HA security appliance

The SonicWall TZ380 High Availability is a paired security appliance configuration that provides redundant firewall protection for small and mid-size sites. Built from the TZ380 platform, this HA setup maintains continuous perimeter or branch security by synchronising configuration and state information between a primary and a secondary unit. The solution supports core network security functions including intrusion prevention, secure VPN connectivity, and centralized management while enabling automatic failover to reduce service disruption.

Advantages

The HA configuration reduces downtime by enabling automatic switchover from the primary firewall to the secondary unit when faults or maintenance events occur. Synchronised policies, sessions and settings cut the time required to restore full security services and help preserve user sessions and VPN tunnels. Centralised visibility and consistent policy enforcement across both appliances simplify administration in distributed or branch environments.

Suitable for

• Small and medium office networks requiring resilient perimeter security
• Branch offices that need continuous VPN connectivity to headquarters
• Environments where high availability and minimal service interruption are priorities

When it may not be suitable

This high-availability configuration is focused on redundancy of the TZ380 platform and does not replace larger data centre-class clustering or multi-node deployments intended for very large networks. Sites that need carrier-grade scalability, large-scale throughput beyond the TZ380 platform limits, or advanced multi-device orchestration may require a different class of firewall solution.

Key specifications

• Deployment: paired primary and secondary TZ380 appliances for high availability
• Primary functions: stateful firewalling, intrusion prevention, secure VPN connectivity
• Failover behaviour: automatic synchronization of configuration and session state for seamless switchover
• Management: supports centralized management tools for policy and device visibility
• Intended use: perimeter or branch office protection with redundant operation

How to use

Install the two TZ380 units in the network perimeter or at the branch site and connect them to the same network segments required for your deployment. Configure one unit as the primary and the second as the secondary in the HA pair, enable synchronization settings, and verify that policies and session-state replication are active. Integrate the pair with your centralized management system if used, and test failover behaviour during a maintenance window to confirm session preservation and policy continuity.

What to consider before purchase

• Confirm that the TZ380 platform capacity and throughput meet your network performance needs
• Verify required physical interfaces and network connectivity for both primary and secondary units
• Assess licensing and subscription requirements for intrusion prevention, VPN and centralised management
• Plan for rack, power and network cabinet space for two units plus cabling and redundancy

Usage recommendations

Deploy the TZ380 HA pair in matched hardware and firmware versions, keep security subscriptions current, and schedule periodic failover tests to ensure the secondary unit will assume full service without data-plane interruptions.