Update #2: Online. Yay.
Update 11th Jun: There seems to have been an IP address conflict on the provider's network for a very short time. Provider support has not been helpful so far. We are working on getting the forum back up within the next few hours. Once it is back online, make sure to report all unexpected site behavior to us immediately.
After a routine reboot for updates a few hours ago, we observed some odd network behavior. We have not heard back from provider support so far. The server has been shut down as a precaution until we know more.