Due to local firewalls I need VPN to visit stackexchange networks. I've already added all sites with suffix "stackexchange.com" to my VPN list, but chatroom is still inaccessible for me. What kind of networks should I add to use the chatroom function? Any help will be appreciated.
There is a list of domains which might be necessary when browsing or participating Stack Exchange on Meta Stack Exchange. Perhaps you're missing
I have uBlock Origin installed, and AFAIK it tells you all domains which are being used for a page. For chat, it's the following list:
stackexchange.com chat.stackexchange.com ajax.googleapis.com cloudflare.net googleusercontent.com gravatar.com imgur.com sstatic.net
cloudflare.net is missing from the list on Meta.SE, so perhaps it's a little outdated.
My solution: As @Glorfindel suggested, I added all the following domains to the PAC list.
ajax.googleapis.com cloudflare.net googleusercontent.com gravatar.com imgur.com sstatic.net stackexchange.com chat.stackexchange.com
After doing so I can visit chatrooms. Therefore a promising solution is to add all domains he mentioned to the list for VPN permission.