Specifications

40 Barracuda Link Balancer Administrator’s Guide
Clustered Barracuda Link Balancers communicate according to the Virtual Router Redundancy
Protocol (VRRP) specification. Both are configured with a single virtual IP address called the VRRP
virtual IP address. This address is serviced only by the active system. If the Barracuda Link Balancer
firewall is enabled, then the VRRP virtual IP address is the default gateway for devices on the LAN.
In the event of a system failure, the other system in the cluster will assume the VRRP virtual IP
address and take on the role of the active system in the cluster. An alert message will be sent to the
administrator.
It is recommended that you use the VRRP virtual IP address to manage the Barracuda Link Balancer
since that always points to the active system. Changes will automatically be propagated to the passive
system.
Physical Connectivity of the Clustered Systems
All Barracuda Link Balancer cluster pairs may be linked using the LAN interface. Certain models also
support a LAN2 interface: if there is a physical LAN port on the front panel, the Ethernet port on the
back is the LAN2 port.
Figure 4.1: Front panel of a Barracuda Link Balancer with LAN port
Figure 4.2: Back panel of the Barracuda Link Balancer
Linking the two systems using the LAN2 port ensures that communication between the two systems
will not be delayed or compromised by other traffic on the LAN. It increases the reliability of the
connection between the two systems and may reduce the time required for failover to occur.
Use a crossover cable between the LAN2 ports to connect the two systems. The LAN2 IP addresses
must be on the same subnet.
Requirements for Clustered Systems
Before joining two systems together, each Barracuda Link Balancer must meet the following
requirements:
• Be model 330 or higher.
• Be the same model as the other Barracuda Link Balancer.