Specifications

Chapter 4: Creating a High Availability Environment 41
• Be activated and on the same version of firmware. The High Availability capability is only
available on firmware 2.x and later.
• Be able to reach the other Barracuda Link Balancer on the LAN interface. This last requirement
applies only if you do not plan to use the LAN2 port for clustering.
Synchronization of Data Between Clustered Systems
When two Barracuda Link Balancers are initially joined, most configuration data, such as WAN
settings, firewall rules, VPN settings and operating mode, is copied from the primary system in the
cluster to the backup system (the system that joins the cluster). This configuration data is
synchronized between the systems on an ongoing basis.
However, these configuration data are unique and are not synchronized between the two systems:
• LAN IP address, LAN2 IP address, DNS servers, default domain and time zone.
• System password, time zone and Web interface HTTP port, as configured on the
Basic >
Administration
page.
• All parameters on the
Advanced > Appearance page.
• The HTTPS port and SSL certificate used to access the Web interface, as configured on the
Advanced > Secure Administration page.
Failover and Failback
There is an automatic failback option that can be configured if you want the originally active
(primary) system to resume link balancing upon its recovery after a failover. This option can be found
on the
Advanced > High Availability page. Alternatively, you can manually switch to the primary
system using the Failback command that is available on the same page.