The Barracuda Load Balancer supports three different operating modes for the most flexibility of any load balancer on the market. Route-path offers the most flexibility, while bridge-path allows deployment without changes to existing IP infrastructure. Direct Server Return allows up to 10GB throughput, ideal for content delivery networks.

Route-path
Route-path provides the most flexibility, allowing load balancing of servers that are  downstream from the Barracuda Load Balancer. In this configuration, the WAN and LAN interfaces of the Barracuda Load Balancer must be on separate logical networks.

Bridge-path
Bridge-path is the simplest deployment to configure. Users may place the Barracuda Load Balancer in line with their existing IP infrastructure, and add load balanced servers as required without changing IP addresses. With this type of deployment, the WAN and LAN interfaces must be on physically separate networks, with the LAN interface on the same logical switch as the servers being load balanced.

Direct Server Return
Direct Server Return (DSR) provides an optimal throughput configuration, while allowing existing servers to maintain their original IP addresses. With DSR, requests come through the WAN interface of the Barracuda Load Balancer and are handed off directly to the real servers via the WAN port, while the servers respond directly to the request through their own interfaces. This implementation requires the use of a Loopback adapter placed on the load balanced servers.

Deployment Chart

LB Topology Requirements By Mode