: If your backup server also acts as a Hyper-V replica host, it likely uses 443 for replication traffic.
The error "Required port 443 for Veeam Backup & Replication is occupied by another application" is a classic collision between modern web-based services and Veeam's deep reliance on HTTPS for its core services. While intimidating at first glance, it is almost always resolvable by methodically identifying the offending process—most often IIS—and either moving it to a different port or eliminating it entirely.
To resolve the issue, you must identify what process currently owns port 443.
Locate the service (e.g., World Wide Web Publishing Service for IIS, or VMware Host Agent ). Right-click the service and select . Change the Startup type to Manual or Disabled . Click Stop , then click OK . Solution 2: Change the HTTPS Binding in IIS : If your backup server also acts as
Temporarily stop the service to allow the Veeam installation to complete.
Developer tools or web servers left running from previous projects.
: If the VBR server also acts as a Hyper-V Replica server, it often uses port 443. : Change the Hyper-V Replication port in Hyper-V Settings > Replication Configuration to a different port (e.g., 444). IIS (Internet Information Services) To resolve the issue, you must identify what
Major Issues After Upgrading to Veeam V13: Port 443 Conflict
Local security dashboards or proxy agents occasionally bind to this port. Step 3: Resolve the Port Conflict
To understand the error, one must first appreciate that Veeam Backup & Replication is not just a file-copy tool—it is a distributed, web-centric platform. Port 443 is the default port for: Change the Startup type to Manual or Disabled
To resolve the error where is occupied, you must identify the conflicting application and either stop it or reconfigure it to use a different port. Starting with Veeam Backup & Replication (VBR) v13 , port 443 is a hardcoded requirement for the REST/Web UI service, and there is no supported way to change it within Veeam itself. 1. Identify the Conflicting Application
: Default web sites or other web applications hosted on the same server. Step 2: Resolve the Conflict
Common culprits:
To find out what that PID is, run: tasklist | findstr [PID_Number] Method B: Using Resource Monitor If you prefer a graphical interface: Press Win + R , type resmon , and hit Enter. Navigate to the tab. Expand the Listening Ports section. Click on the Port column to sort numerically.