The following content is a brief and unofficial prerequisites guide to upgrade from NetScaler Gateway 10.5.x.n to NetScaler Unified Gateway 11.x.n prior to deploying in a PoC, Pilot or Production environment by the author of this entry. The views, opinions and concepts expressed are those by the author of this entry only and do not necessary conform to industry descriptions or best practises.

Shortened Names
VIRTUAL APPLIANCE – v/a
NETSCALER GATEWAY – nsg
NETSCALER UNIFIED GATEWAY – nug
VIRTUAL IP ADDRESS – vip

Deployment Preparation Overview (DRAFT & MAY CONTAIN ERROR(S))
The following is an upgrade process that I utilise within my own home lab. Please ref to http://docs.citrix.com/en-us/netscaler/11/license-upgrade-downgrade/upgrade-downgrade-the-system-software.html for an accurate and official upgrade process.

1: Download the firmware of your choice if more than one is available at – http://www.citrix.com/downloads/netscaler-adc.html. Please note that your will require either a valid Citrix account to download the firmware.
2: Upload the *.tgz file you downloaded to the following location on your NS V/A “/var/install“. Once you have confirmed its successfully uploaded disconnect and close your (s)FTP application. I use WinSCP myself which can be downloaded at – https://winscp.net/ as my (s)FTP client.
3: Open a Secure Shell (SSH) connection to the NS V/A and enter in the username and password access details where prompted. Once your have successfully logged in type “shell” then type “cd /var/nsinstall” to change to the nsinstall directory and then type “ls” to confirm the uploaded file is there.
4: Now to unpack the tarball package by typing in “tar –xvzf build_X_XX.tgz”, where build_X_XX.tgz (TIP: Enter in B and press TAB to complete typing the name of the file) is the name of the NS firmware build that we will be upgrading to. Once the tarball is successfully unpacked type in “ls” verifying that you can see the extracted files from the tarball.
5: Now type in “./installns” to begin the upgrade process and where prompted type in “Y” to reboot the NS V/A
6: Move to your hypervisors mgmt. console and watch the NS CLI reboot and once you can see the NS login prompt within the CLI navigate to the NS mgmt. IP addr and login using your NS access details and verify that the NS V/A has been successfully upgrade to your firmware of choice by looking at the firmware version in the top right-hand corner of the WebUI.