We have had ADFS setup with an internal and proxy server working well for about a month. This past week, the proxy server stopped working, just returning a "Service Unavailable - http 503 error". The internal server (the ADFS host) continues to work fine.
I have tried almost everything from uninstalling the Remote Access role on the proxy server, re-exporting and importing the SSL cert from the ADFS server, and re-setting everything up from scratch on the proxy server, still to no resolution. When I go through the remote access setup process on the proxy, it says that ADFS is configured correctly and there are no errors in the event log. But still get the 503 error.
What else should I be looking at?
Both servers are 2012 R2.