Our web server was just switched to a V-LAN with some very strict firewall rules. Basically they closed every inbound and outbound port unless we specifically needed it.
We have some services running locally on the server that handle requests on specific ports (58585 and 45454), but the requests are made by the web application itself to 127.0.0.1.
This stopped working once they switched our web server to the new V-LAN. Is it possible the router can actually BLOCK localhost traffic? Windows Firewall is disabled so it cannot possibly be the culprit.
Turns out the service was not up and running.
However, the lesson to be learned is that 127.0.0.1 can NOT be affected by a router firewall because the packets are completely restricted to the local computer.