If I recall correctly, you have a script at logon that call the program required with the IP address of the system. I remember having some issues with the SSO also, but in the end I made it work for my test account. I tried it a few months ago, and It didn't fit with us because of the Blacklist db that was too small. It looks more like something I'd see in a Hotel/Airport/coffee shop. Honestly that DNS Redirector doesn't look like a cooperate solution. I'd rather use DNS filtering as presumably it would use less resources on my VM servers than something like a proxy server would, which can use a fare amount of resources to keep up with demand, DNS servers on the other hand are a lot more lightweight. I'm not paying for a web filter solution I will preferably use NxFilter or make my own Squid box. Why would I go for a paid solution just to get auto-updates? It's super easy to setup WGET on windows with a script to download files, move the correct file to the needed location and then cleanup when down, and it could even be run by the task scheduler. We're still using DNS Redirector today - auto-updates categories, and doesn't require Java - not much AD integration beyond password bypass, but that's all we need. I tried it - did not like that it didn't auto-update the blacklist categories, and technically the sources of which are for non-commercial use - did not like that it required Java on the server.

Nxfilter port 53