I have two Linux servers acting as a reverse proxy between my Exchange server and the internet. The newest server is RHEL 8.7.
When I attempt to cURL to OWA from the RHEL server I am getting the following response:
<html><body><h1>503 Service Unavailable</h1>
No server is available to handle this request.
</body></html>
When I attempt the same request from the Ubuntu server, I get the HTML I'm expecting from OWA.
So far the troubleshooting I've done is as follows:
- Both Linux servers are on the same network.
- I've tried disabling the firewall on the Exchange server, but that made no difference.
- I've tried enabling ALL traffic between the vLANs, but that made no difference.
- I've tried disabling firewall rules on the RHEL server, but that made no difference.
I'm at a complete loss as to what else I can do to troubleshoot. Any ideas?