Many times I found myself having to demonstrate that the communication between the Unified Access Gateway and the Connection Servers was not working due to problems with poorly configured firewall rules. A very useful test is to connect to the UAG console and launch the classic CURL command:
curl -v -k https://<FQDN or IP ADDRESS CS>:443/
the outcome of which is as follows if the connection is ok (HTML output)
![](https://vmvirtual.blog/wp-content/uploads/2024/01/image-1024x543.png)
or the following if the connection is not enabled on the firewall
![](https://vmvirtual.blog/wp-content/uploads/2024/01/image-1.png)
More info and tools here: