Is the IP address 255.255.255.255? If that’s the case, it might in fact be DNS. Workaround here:
It definitely does sound like a firewall issue though, especially given that it works locally. Usually we’d recommend using a simple tool like telnet just to see if you can connect to port 17000 via TCP. Because that tool’s not installed on most system’s these days it’s a bit of a pain. I did find an example of doing the same with PuTTY that is worth a look. Essentially, if PuTTY just sits there doing nothing, TCP is working.