I got it resolved through support - they switched me to a different server on their end. So at least support was available after hours. Hopefully the issue itself is rare. I've had several such downtimes this year, but this is first time in months, and could be due to some external internet routing issues as well, as I'm on the west coast. (unless it affects more people)
I'm in discussions with these guys as well for something I'm interested in. On the site it says linux is buggy. is it? http://www.nanex.net/2020/nxcore-downloads/ " Our Linux version is still a beta product and not fully supported. It has some bugs, both known and unknown. It is developed, tested and runs best in a Debian/Ubuntu environment. For a production environment, it is HIGHLY recommended that you use our Windows version, instead. " Also, Guru / Pragmatic, are you hosting in their colocation? They are on cogent and I'd like to get a server as close them as possible.
I host on the west coast, so far from them. Sometimes when I have issues they switch me to a different server (on Nanex end) and this usually resolved my problem, while being near them should work best indeed.