The NetScaler Application Delivery Controller (ADC) is a Citrix® Systems core networking product. ADC improves the delivery speed and quality of applications for an end user. The product helps business customers perform tasks such as traffic optimization, L4-L7 load balancing, and web app acceleration while maintaining data security.
NetScaler ADC monitors server health and allocates network and application traffic to additional servers for efficient use of resources. It also performs several kinds of caching and compression. It can be used as a proxy server to process Secure Socket Layer (SSL) requests instead of servers (SSL offloading).
This blog covers the basic Hyper Text Transfer Protocol (HTTP) site load balancing configuration.
The following steps comprise the typical load balancing traffic flow for NetScaler:
The following image shows this traffic flow:
Before configuring NetScaler load balancing, perform the following steps:
MGMTport for management access.
To configure NetScaler load balancing, perform the following steps:
To add the backend servers, perform the following steps:
Connect to the management IP of your NetScaler.
Select Login > Configuration > Traffic Management > Load Balancing > Servers.
To create a service group, perform the following steps:
Group these servers together in a service group configuration by choosing Traffic Management > Load Balancing > Service Groups.
To change the monitoring, perform the following steps:
Change the monitoring from
To create a virtual server, perform the following steps:
Create a virtual server by choosing Configuration > Traffic Management > Load Balancing > Virtual Servers.
Give the virtual server a name.
Set the protocol to
Specify the IP address, which should be the VIP that NetScaler presents to the outside world.
Set the port to
To test the configuration, use different web Welcome pages on each of the servers. When you refresh the page, you can see that the NetScaler is doing its job and balancing the requests across both back-end web servers as shown in the following image:
Use a load balancer to distribute the load across multiple web and application servers. Load balancers can also do SSL offloading to expose the application or URL to the Internet in a secure way by installing an SSL certificate. If you have only one back-end server with SSL offloading, you should install the SSL certificate on the server and expose the server to the Internet with all the appropriate security measures and patches. You should open only the required ports on the firewall for the LBVIPs or the back-end server with SSL offloading when you expose it to the Internet.
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