Specifications

Load Balancing Concepts 19
Load Balancer Deployment Options
Services on the Barracuda Load Balancer can be deployed in the following three modes:
Route-Path (Recommended)...............................................................19
Bridge-Path........................................................................................ 21
Direct Server Return..........................................................................22
Choose the deployment mode for the Barracuda Load Balancer based on the type of network
configuration that currently exists at your site as well as on the types of Services you wish to load
balance. The recommended mode is Route-Path because it requires the least amount of invasive
changes to your existing network configuration. For Services that have high outbound traffic,
enabling the Direct Server Return option is recommended for the Real Servers that are producing that
traffic.
All of these deployment modes require specific network configurations. However, the Barracuda
Load Balancer must be in either Route-Path or Bridge-Path mode. Direct Server Return is an option
that you may choose for each Real Server.
Table 2.2 shows the number of logical and physical networks required by each deployment method.
Route-Path (Recommended)
Route-Path deployment is the most frequently used deployment method, providing the most
flexibility by allowing load-balancing of any server in a downstream route. With Route-Path, the
WAN and LAN interface of the Barracuda Load Balancer must be on separate logical networks. The
load-balanced servers are moved to a new private network and the Barracuda Load Balancer takes
control of the publicly-accessible IP addresses (VIPs) used to reach the Services.
The following table describes the advantages and disadvantages of deploying your Barracuda Load
Balancer in Route-Path mode.
Table 2.2: Deployment Method Details
Deployment Method Logical Networks Physical Networks
Route-Path (Recommended) 21+
Bridge-Path 1+ 2
Direct Server Return 1 1
Advantages Disadvantages
Minimal network re-designing; works with
existing physical configurations
The Barracuda Load Balancer must be the default
gateway for all downstream Real Servers
Fast High Availability failover Real servers must be on a logically separate network
from the Virtual IP addresses.
Can load-balance any downstream server All return traffic must be directed through the Barracuda
Load Balancer
No changes to Real Server setups other than
changing their IP addresses