Overview

Citrix ADC, formerly known as Citrix NetScaler, is a feature-rich application delivery controller (ADC) that plays a vital role in optimizing the delivery of applications to end users. It offers advanced load balancing, acceleration, security, and offload capabilities to ensure the smooth and secure functioning of applications across networks.

Here are some features and functionalities of Citrix ADC:

  • Load Balancing: Citrix ADC distributes incoming traffic across multiple servers to ensure optimal resource utilization and high availability of applications.

  • Traffic Management: It provides advanced traffic management capabilities, including content switching, SSL offloading, compression, caching, and TCP optimization, to enhance application performance and user experience.

  • Security: Citrix ADC offers robust security features such as application firewall, SSL VPN, authentication, authorization, and encryption to protect applications and data from various cyber threats.

  • Global Server Load Balancing (GSLB): GSLB allows organizations to distribute traffic across multiple data centers based on proximity, availability, and server health to ensure optimal application delivery and disaster recovery.

  • Application Acceleration: It optimizes application performance by accelerating content delivery, reducing latency, and improving response times for end users.

  • Scalability: Citrix ADC is highly scalable and can handle a large number of concurrent connections and transactions, making it suitable for enterprise-scale deployments.

  • Unified Gateway: It serves as a unified gateway for accessing applications, desktops, and data securely from any device, location, or network.

  • Analytics and Monitoring: Citrix ADC provides comprehensive analytics and monitoring capabilities to gain insights into application performance, user behavior, and security threats, enabling proactive management and troubleshooting.

  • Integration: It integrates seamlessly with Citrix Virtual Apps and Desktops, Citrix Workspace, and other Citrix solutions to deliver a complete application delivery and virtualization platform.

  • Multi-Tenancy: It supports multi-tenancy, allowing service providers and enterprises to securely isolate and manage multiple applications and tenants on a single ADC instance.

Installing Citrix AD NetScaler.

To set up and configure a NetScaler VPX appliance, here are the steps:

  • Download the NetScaler VPX appliance image from the mycitrix.com Web site using your credentials.
  • Select the appliance image depending on your Hypervisor. it’s currently the following Hypervisor model:
  • On-Premise Hypervisor models: Citrix Hypervisor, VMware ESX hypervisor, HyperV, Nutanix AHV, and generic KVM.
  • CLoud-based Virtual Machine providers: AWS, and Azure

  • Extract the image, and install the appliance by using the Import option depending on your hypervisor.

  • Turn the VM on, follow the setup instruction, and Log on to the console by using the nsroot credentials.

  • Download the license for the NetScaler VPX appliance from Citrix by using the Media Control Access (MAC) address of the Virtual Machine.

  • Note: The MAC address on the Virtual Machine in the Network tab of the VM. Ensure that you use this value without embedded spaces or colons.
  • Form the local computer, access the appliance from a Web browser using a Web address similar to the following: http://<IP_Address_of_NetScaler_VPX_Appliance>
  • When installing the appliance, the installation process prompts for the IP address and the network mask. Run the ifconfig command to verify the IP address of the appliance.
  • Log on to the Configuration utility of the appliance by using the nsroot credentials.
  • On the Navigation bar, expand System.
  • Click Licenses.
  • Click the Manage Licenses link.
  • Locate the license on the local computer and add the license to the appliance. You can also use an FTP utility to upload the license to the appliance.

Upgrading Citrix ADC Netscaler.

Citrix offers a security update. It’s advisable to update the Citrix NetScaler periodically, ensuring there’s not any security hole in the wild.

Here’s a general outline of the steps to update the Citrix ADC Netscaler:

Preparation

  1. Login to Citrix ADC via web GUI, go to backup menu, perform backup config, and download it to your computer/local computer. This to ensure you have a backup config prior to this update.
  2. Click Save button to ensure any pending changes is permanently saved, so no any configuration lost after the reboot/upgrade process.
  3. If this is a VM applicance, take a VM Snapshot first.

This is just a backup before updating, ensuring you can easily roll back this Netscaler VM if something bad happens after this update.

  1. SSH to ADC server, enter shell, go to var/nsinstall directory and create a new directory with release version name.

This is optional, but recomended. By storing the update on a new directory and name it with release number, we can easily identify and remove this directory, in case there’s disk space issue in the future.

  1. Prior to update, the installer detect the freespace on the system, and requires some space more than 75% before starting. So make sure you have more than 75% space on the system.

Update steps:

Citrix recomends to the perform the update from shell rather than GUI.

Upload the update into ADC Netscaler.

  1. Login to ADC using Winscp (SFTP protocol)
  2. Go to var/nsinstall:
cd var/nsinstall
  1. Create a new directory and copy the newly downloaded build to this directory.
mkdir build-13.0-91.13_nc_64
  1. If the /var directory space more than 75%, deleting old files (old installer version) on nsinstall directory first.

SSH into ADC Netscaler

  1. Login to ADC Netscaler server via ssh using Putty, or Powersahell.
  2. Enter
shell
  1. Go the new directory you create in step 4:
cd var/nsinstall/build-13.0-91.13_nc_64
  1. Extract the .tgz file:
 tar -zxvf <filename.tgz>

Remember that this update requires more than 75% before starting. So make sure you have more than 75% space on the system, before starting this update.

  1. Run the update program:
./installns
  1. Wait for the installation and reboot.

Verify the ADC netscaler

After the updating process is completed, verify the connection to CVAD machines inside or outside by loging in via **Citrix Workspace, and verify the apps, ensuring all apps that previously running well is also running well after this update. You can still keep the checkpoint for a few days, just in case.

Conclusion

Citrix ADC is a versatile and powerful solution for optimizing application delivery, enhancing security, and improving the user experience in Citrix environments. Updating the system regularly is required, ensuring the system stays secure and protected against evolving threats, and fixes any bug.