DNS resolution is one of the most common issues that we see while troubleshooting VDA registration issues. Whenever you see an unregistered state on the Studio console for VDA host machines and you are sure that the list of DDC servers is configured correctly, you should start troubleshooting for network and DNS resolution.
Try starting with the ping command that needs to be run from the VDA and DDC servers respectively. You should be able to ping and resolve the FQDN name for the DDC servers from the VDA host machine and vice versa.
You start with the ping command and find that you are not able to ping the Delivery Controller from the VDA machine, as shown in the following screenshot:
The next step we need to perform is to verify its entry in the DNS, so we need to run the nslookup command, as shown here:
Citrix Studio shows the machine as unregistered:
We found that the system administrator has...