Specifications

Managing the Barracuda Load Balancer 49
In Weighted Least Connections, the Barracuda Load Balancer considers the number of live
connections that each Real Server has, as well as the weight values. The Real Servers with higher
weight values will receive a larger percentage of live connections at any one time. The Barracuda
Load Balancer dynamically checks the number of live connections for each Real Server.
Weighted Least Connections is the recommended choice.
To configure the Default Scheduling Policy for a Service:
1. From the Basic > Services page, click Edit for the Service you wish to configure. The Service
Detail
page will appear.
2. In the Default Scheduling Policy dropdown, choose either Weighted Least Connections or
Weighted Round-Robin.
3. Click Save Changes.
Configuring Intrusion Prevention
The Basic > Intrusion Prevention page lets you enable and disable the Intrusion Prevention System
of your Barracuda Load Balancer. Refer to Intrusion Prevention System on page 10 for more
information about what the Intrusion Prevention System (IPS) is and how the Energize Updates
feature works.
By default, IPS is disabled for any newly created load-balanced Service.
You can enable or disable IPS for an individual Service by selecting or deselecting the IPS option on
the
Basic > Services > Edt > Service Detail page. You can enable or disable IPS for the entire
Barracuda Load Balancer from the
Basic > Intrusion Prevention page. The Basic > Intrusion
Prevention
page displays a list of all of the Services and whether IPS is enabled for each one.
To test if the IPS is working on the Barracuda Load Balancer, there is a simple URL that will generate
a test IPS catch. To test with this URL, create or locate a Web Service (with at least one Real Server)
on port 80 from the Basic > Services page. Then type the following address in your browser window:
http://VIP/?Barracuda-IPS-Web
where VIP is the VIP of the Web Service. If IPS is on, it will block this. Your browser will give an
error because the connection will be immediately rejected. There should also be an IPS catch in the
Event Log in
Basic > Event Log, although it may take up to a minute to appear.
Creating a High Availability Environment
In order to increase the robustness of your network, you can install and configure a second Barracuda
Load Balancer to act as a backup to your primary Barracuda Load Balancer. The backup Barracuda
Load Balancer monitors the primary Barracuda Load Balancer and takes over the load-balancing
operations automatically and quickly if the primary fails for some reason.
Requirements for High Availability (HA)
Some network environments may be less suitable to clustering two Barracuda Load Balancers. For
example, if you have multiple network segments that each require different policies, it may be better
to provide a dedicated, unclustered Barracuda Load Balancer for each segment. This way, you can
configure each Barracuda Load Balancer separately without the configuration settings propagating to
the other systems.