Required Port 443 For Veeam Backup Replication Is Occupied By Another Application Link

Windows:

tasklist /fi "PID eq <PID>"

Get-Process -Id <PID>

Linux (if applicable):

After freeing port 443:

Before you can fix the issue, you must determine which application is currently listening on port 443. You can do this via the Command Line or PowerShell. Windows:

Required port 443 for Veeam Backup & Replication is occupied by another application — how to identify and resolve

Q: Can I use a different port for Veeam's HTTPS communication?
A: No. The main Veeam Backup Service hardcodes port 443 for internal communication with mount servers, proxies, and repositories.

Q: What if I cannot stop the conflicting application?
A: Move Veeam to a dedicated physical or virtual machine. Do not co-host with other web-based enterprise applications. Find the process name from the PID: tasklist

Q: Does Veeam Agent for Windows use port 443?
A: Only when communicating with a Veeam Backup & Replication server. The agent itself does not listen on 443.

Veeam Backup & Replication is designed to work best on port 443. Changing Veeam’s port can cause issues with Cloud Connect providers, Veeam Agent management, and WAN Accelerators. It is best practice to move the conflicting application to another port.

Scenario 1: IIS (Internet Information Services) is using Port 443 If System (PID 4) is holding the port, it is likely IIS. Or in PowerShell: Get-Process -Id <PID>

Scenario 2: VMware Update Manager If you are running Veeam on a vCenter Server or a server with Update Manager installed:

There are two main ways to resolve this: change the port for the conflicting application (Recommended) or configure Veeam to use a different port.

Port 443 is the standard HTTPS port. Common applications that conflict with Veeam include:

| Application / Service | Typical Context | |----------------------|------------------| | IIS (Internet Information Services) | Default web server on Windows; may host other websites or management consoles. | | Microsoft Exchange Server | Uses port 443 for Outlook Web Access (OWA) and Exchange Admin Center. | | Skype for Business / Teams (on-prem components) | Uses port 443 for web conferencing and mobility services. | | Apache / Nginx | Third-party web servers running on same Windows VBR server. | | VMware vCenter Server (embedded) | If Veeam is installed on a vCenter Server (not recommended). | | SQL Server Reporting Services (SSRS) | Uses port 443 for report manager. | | Third-party antivirus / proxy services | Some inject a local HTTPS inspection proxy. |