VMware Horizon Client ID explained

One of my customers asked me yesterday what Client ID represents on the Horizon Administrator Console.

My first reaction was to assume it was the MAC address of the Client device but quickly realized that was far from being true. I couldn’t find official documentation, so thought I ll write this one up.

“Client ID is the unique identifier that is generated by Horizon Connection Server for every client that connects to it”.

It is a random number generated by the combination of MAC address of the endpoint and the client type (HTML, iOS, Windows, Linux).

For egs, a Windows endpoint(with a single MAC address) installed with Horizon Client  can potentially have multiple Client IDs based on number of client types used to access VDI. One for the Windows thick client and a different Client ID gets created for each browser(Firefox, Edge, Chrome).

The important thing to note is that Client ID will persist across sessions if it is the same device/browser combination.

In the below example, from the same Macbook I am accessing Horizon using two different Horizon Clients clients 1) HTML client which is my Chrome browser and 2) MacOS client.

Access from MacOS Client

I am accessing two different desktop pools APAC-Win10AE and APAC-Win7 and the Client ID remains the same. Notice APAC-RDS when accessed using HTML Client shows a different Client ID.

Access from HTML Client

I am accessing two different desktop pools APAC-Win10AE and APAC-RDS and the Client ID remains the same. Notice APAC-Win7 Pool when accessed using MacOS Client shows a different Client ID.

Side Note: Client ID also helps Horizon Server to uniquely identify clients for several purposes such as 1) Kiosk mode login 2) allow or deny single or multiple sessions for a single Desktop Pool.