If the Veeam server is intended to be a dedicated backup appliance and IIS or other web services were installed accidentally or are not needed:
: Hosting a local corporate website, intranet portal, or management console.
After applying your fix, ensure that everything works correctly:
Authentication and traffic routing for the Veeam self-service web UI and REST API. Step 1: Identify Which Application is Using Port 443 If the Veeam server is intended to be
To confirm exactly which application is holding the port, perform the following steps on the Veeam Backup Server:
Older desktop versions famously utilized port 443 as a fallback for incoming connections.
Method 1: The "Upgrade & Pivot" Strategy (Recommended for Third-Party Apps) Method 1: The "Upgrade & Pivot" Strategy (Recommended
If you must run both applications on the same server, change the port used by the non-Veeam application.
: If your backup server also acts as a Hyper-V replica host, it likely uses 443 for replication traffic.
: Beyond IIS, any web server like Apache, Nginx, or a reverse proxy service configured for HTTPS will occupy port 443. After some discussion with the team, they decided
After some discussion with the team, they decided to move the Acme Secure Gateway to a different server and change its configuration to use a different port. They also updated the Veeam configuration to use a new port, and everything was back to normal.
If your Veeam server is also acting as a web server, IIS likely has a "Default Web Site" bound to 443.