Required Port 443 For Veeam Backup & Replication Is Occupied By Another Application |link|

This is a common and critical issue when deploying Veeam Backup & Replication (VBR). The error indicates a port conflict on TCP port 443.

Using PowerShell: Run the following command to see the process name directly:

Common pitfalls (for graders to watch)

• Ignoring HTTP.sys reservations and only checking IIS.
• Forgetting to check certificate private key permissions.
• Recommending deletion of certificates without backup.
• Not accounting for clustered/HA setups where VIP binds to 443.
• Not verifying client connectivity after changes.

This conflict typically occurs because another service is already using the default HTTPS port on your backup server. Here is how to identify and resolve the conflict. 1. Identify the Conflict To find out which application is blocking Veeam, use the Command Prompt (run as Administrator): Find the Process ID (PID): This is a common and critical issue when

VMware vCenter/Workstation: If installed on the same machine, VMware services default to port 443.

2. Microsoft Exchange Server

If Veeam is installed on an Exchange Server (not recommended but sometimes done in small environments), Exchange’s front-end services (Outlook Web App, ECP, ActiveSync) listen on port 443. Ignoring HTTP

Action: Opened IIS Manager → Default Web Site → Bindings → removed HTTPS:443 binding → Restarted IIS (iisreset).
Result: Veeam Backup Service started normally.

Use PowerShell: Run the following command to find the Process ID (PID) using the port:Get-NetTCPConnection -LocalPort 443 | Select-Object LocalAddress, LocalPort, OwningProcess, State. This conflict typically occurs because another service is

B. Change the conflicting application’s port

Example – IIS: