Horizon – Upgrade Unified Access Gateway to v.2512

22. Dec 2025

Welcome to my Omnissa Unified Access Gateway series. The new version of Unified Access Gateway, 2512, was GA December 16th 2025. In this section I will describe how I upgraded my UAG’s to v. 2512. According to Omnissa’s official documentation, this should be done as step 8 in the supported update sequence.

To check out all the new features and changes with Unified Access Gateway 2512, read the release notes from Omnissa posted here: Unified Access Gateway Release Notes. Below are some of the most important changes.

What’s New

Support for Horizon in extra large configuration

Unified Access Gateway now supports extra large configuration for Horizon 8 deployments and can handle up to 4000 Horizon connections. See Unified Access Gateway Sizing Options.

Support for adding multiple TLS certificates for Internet interface

Unified Access Gateway now supports binding up to 10 TLS certificates to the Internet interface for Horizon and Web Reverse Proxy end user flows, with automatic certificate selection using SNI. For more information, see TLS/SSL certificates.

Enhancements to Tunnel and Blast URLs on Horizon Settings

Added support for validating Host headers with port numbers, auto generated from the values specified against the Tunnel and Blast External URLs (including additional external URLs), ensuring correct matching when port is present in Host header of the HTTP request arriving at Unified Access Gateway. For more information, see Configure Horizon Settings.

First, I download the necessary installation media and Powershell scripts from Omnissa Customer Connect to my deployment server.

Next, I login to the Admin-GUI and export the settings before I start upgrading.

I copy the new OVA-file and the updated uagdeploy Powershell files to my working directory

Next, I edit the ini-files with new ova filename

In my previous upgrades, I have reconfigured the SSL Certificates after deployment. This time, I will use the ini-file to configure the SSL Certificate. I first export the certificates from the HAProxy server as described here: HAProxy Export certificates. Next, I need to encrypt my key with RSA, running the command documented by Omnissa here: Convert Certificate Files to One-Line PEM Format.

_{openssl rsa -in c:certdesktopprivkey.pem -check -out c:certdesktopprivkey_rsa.pem}

I copy the “privkey_rsa.pem”-file to my working folder and adjust the SSLCert section in the ini-file

Finally, I deploy the UAG’s with the new ova-file using the existing ini-files. As we can see from the screenshot below, the script automatically shuts down the existing UAG’s and deletes them, before deploying the new UAG’s using the settings I defined in the ini-files. NOTE: When executing the uagdeploy.ps1 script, I previously used PASSWORD PASSWORD false false no as parameters, but these no longer works. I replaced PASSWORD with the passwords I wanted to use instead, which works flawlessly. For details see: Using PowerShell to Deploy Omnissa Unified Access Gateway

It is also important to check out the new demands due to the “Re-Write Origin Header” property, as documented by Omnissa here: Configure Horizon Settings

Reference: Cross-Origin Resource Sharing (CORS) with Horizon 8 and loadbalanced HTML5 access. (85801)

I adjust my locked.properties file as shown below and restart my Connection Servers

When the upgrade is complete, I log in and check that all my settings are correct,

I also login to Horizon Administrator Console, where I can see that the Gateways are up and running the new version

This completes the UAG upgrade, and I do a test by logging in through the HAProxy and UAG’s.

Unified Access Gateway Release Notes

UAG Documentation:

Omnissa Documentation:

Unified Access Gateway – Upgrades

Unified Access Gateway planning, deployment etc.

Disclaimer: Every tips/tricks/posting I have published here, is tried and tested in different it-solutions. It is not guaranteed to work everywhere, but is meant as a tip for other users out there. Remember, Google is your friend and don’t be afraid to steal with pride! Feel free to comment below as needed.

Del dette: