Required Port 443 For Veeam Backup Replication Is Occupied By Another Application Link (2026)

Sometimes, netstat shows that the "System" process is listening on 443, but IIS is not installed. This is often caused by Windows Remote Management (WinRM) listening on port 443 for HTTPS listeners.

To check and remove this listener:

Topic: Port 443 Conflict Preventing Veeam Backup & Replication Service Initialization Severity: High (Service Disruption) Common Error Message: Unable to start Veeam Backup Service. The required port 443 is already occupied by another application.

On a typical Windows Server, the most common offenders are:

| Application / Service | Typical Use Case | | :--- | :--- | | IIS (Internet Information Services) | Default Web Site, WSUS, or any internal web app. | | Microsoft SQL Server Reporting Services (SSRS) | Uses HTTP.SYS to listen on Port 443 for reports. | | Skype for Business / Teams | Can bind to ports unexpectedly. | | Remote Desktop Gateway (RD Gateway) | Uses HTTPS (443) for secure RDP connections. | | Syslog / SIEM agents | Some agents redirect SSL traffic via 443. | | Antivirus Web Filtering | Symantec, McAfee, or Cisco AMP can proxy HTTPS. | | Hyper-V Host Service | Certain Hyper-V configurations use port 443 for management. | | Docker Desktop (Windows containers) | The MobyLinuxVM engine may bind to 443. | | Previous Veeam Installation | Leftover services from a failed uninstall. |

Before diving into solutions, it is critical to understand why Veeam insists on Port 443. Veeam Backup & Replication uses Port 443 for several key functions:

If another application is squatting on Port 443, Veeam cannot start its core listening services, leading to installation rollbacks or failed service startups.

By identifying the process holding the port and deciding whether to move the intruder or move Veeam, you can resolve the installation error and get your backup infrastructure up and running.

When upgrading to or installing Veeam Backup & Replication (VBR) v13, many administrators encounter the error: "Required port 443 for Veeam Backup & Replication is occupied by another application". This occurs because port 443 is now hardcoded for the mandatory Veeam REST API Service and Web UI in version 13. Why Port 443 is Required

In Veeam v13, port 443 is used for the Identity Service and REST API Gateway. If another service is already listening on this port, the Veeam services will fail to bind, preventing the VBR console from starting or the upgrade from completing. How to Identify the Conflicting Application

To resolve the conflict, you must first identify which process is currently using port 443.

Command Line: Open a command prompt as administrator and run netstat -anob | findstr :443. This will display the Process ID (PID) and the name of the executable using the port.

PowerShell: Use the command Get-NetTCPConnection -LocalPort 443 to find the associated PID.

Common Culprits: Frequently conflicting services include IIS (Internet Information Services), Hyper-V Replication, Remote Desktop Web Access, or third-party security agents like Qualys. Solutions and Workarounds

Currently, there is no supported method within the Veeam installer to change the port for the REST API Gateway. You must free up the port on the host server: Stop or Reconfigure the Conflicting Service:

If IIS is using the port, you can change its binding via the IIS Manager (InetMgr.exe) by selecting "Edit Bindings" for the website and changing 443 to a different port.

If Hyper-V Replication is the cause, go to Hyper-V Settings > Replication Configuration and change the port from 443 to another value (e.g., 444).

Temporary Stop for Upgrade: If the conflicting application is only needed occasionally, stop the service, complete the Veeam v13 upgrade, and then attempt to restart the other service. Note that Veeam v13 services will still fail to start if the port is occupied later.

Use a Dedicated Server: Veeam recommends installing VBR on a dedicated server to avoid port conflicts with other web-facing applications. Troubleshooting Connectivity

Major Issues After Upgrading to Veeam V13: Port 443 Conflict

When upgrading to Veeam Backup & Replication (VBR) v13 is a strictly required, hardcoded dependency for the new Veeam Web Service/API Gateway

. If this port is occupied by another application, the VBR services will fail to bind, preventing the software from starting or completing an upgrade. Veeam Community Resource Hub Common Conflict Culprits

Port 443 is the standard for HTTPS, making it a high-traffic area. Frequent "squatters" include: Hyper-V Replication: By default, Hyper-V uses 443 for its replication traffic. IIS (Internet Information Services):

Web servers or Microsoft-related services like SQL Reporting Services often bind to this port. Other Web Servers:

Apache, Nginx, or management interfaces for third-party software. How to Identify and Evict the Occupant To reclaim the port for Veeam, follow these steps:

Major Issues After Upgrading to Veeam V13: Port 443 Conflict

Resolving Port 443 Conflicts in Veeam Backup & Replication In modern data centers, port 443 (HTTPS) is a critical gateway for web services, APIs, and secure communications. For Veeam Backup & Replication (VBR) v13, port 443 is a hardcoded requirement for the REST API and Web UI services. If this port is occupied by another application, the Veeam upgrade will be blocked, or the services will fail to start. Identifying the Conflicting Application Sometimes, netstat shows that the "System" process is

Before resolving the conflict, you must identify which process is currently holding the port.

Command Line: Open a command prompt as an administrator and run:netstat -ano | findstr :443

Locate the PID: The right-most column of the output is the Process ID (PID).

Task Manager: Open Task Manager, go to the Details tab, and match the PID to find the application name.

PowerShell Alternative: Use Get-NetTCPConnection -LocalPort 443 to directly see the OwningProcess. Common Conflicting Services

The most frequent culprits for port 443 occupation on a Windows server include:

Major Issues After Upgrading to Veeam V13: Port 443 Conflict

Resolving Port 443 Conflicts in Veeam Backup & Replication v13

Veeam Backup & Replication (VBR) v13 introduces a strict requirement for TCP port 443, which is used for the new hardcoded REST API and Web UI services. This shift from previous versions can cause critical installation or upgrade failures if another application—such as IIS, VMware Workstation, or Hyper-V Replication—is already listening on that port. Identifying the Conflicting Application

If you encounter the error "Required port 443... is occupied by another application," you must first identify the process holding the port. Open an elevated Command Prompt or PowerShell. Run the following command:netstat -ano | findstr :443 Locate the PID (Process ID) in the rightmost column.

Find the application name in Task Manager (under the "Details" tab) using that PID. Common Conflicting Services

Hyper-V Replication: Often uses 443 for HTTPS-based replication.

IIS (Internet Information Services): Default web servers often bind to 443 for HTTPS.

Windows Remote Management (WinRM): Sometimes causes conflicts that prevent the VBR console from loading.

Other Backup Agents: Third-party agents or previous Veeam components might still be holding the port. Solutions and Fixes

In VBR v13, port 443 is hardcoded for the API Gateway and Web service; there is currently no supported way to change this within the Veeam configuration itself. Therefore, you must move the other application to a different port. For Hyper-V Replication Servers: Navigate to Hyper-V Settings > Replication Configuration.

Change the specified port from 443 to a different available port (e.g., 444).

Update the Replica Server Port in the settings for each VM on every host to match the new port. For IIS Sites: Open IIS Manager and expand Sites. Right-click the site using 443 and select Edit Bindings.

Change the HTTPS port to another value or assign the site a specific IP address to free up 443 on "All Unassigned". For WinRM Conflicts:

Reviewers on the Veeam R&D Forums have noted that stopping the Windows Remote Management (WS-Management) service entirely may be necessary if it prevents the console from loading. Next Steps

Before proceeding with your upgrade, verify the full list of required connections in the Veeam Ports List Finder to ensure all other necessary traffic (like ports 2500–3300 for data transfer) is clear. Veeam B&R 13 Change Web Service Port 443

This error typically occurs during the installation or upgrade to Veeam Backup & Replication v13 (or newer), as port 443 is now hardcoded and required for the Veeam Web Service/API Gateway

. Because this port is fixed, the Veeam services will fail to bind and start if another application is already using it Quick Fixes for Common Conflicts

If you encounter this conflict, identify the application using port 443 and apply the relevant solution: Hyper-V Replication Conflict

: This is a common issue if the VBR server is also a Hyper-V Replica server Hyper-V Settings Replication Configuration Change the port from to something else (e.g., 444)

Update the replica settings for each VM to match this new port Windows Remote Management (WinRM) Topic: Port 443 Conflict Preventing Veeam Backup &

: In some environments, WinRM or WS-Management may occupy this port Temporarily stop the Windows Remote Management

service to allow the Veeam console to load or complete its upgrade General Web Services

: Other web servers (like IIS or Apache) or third-party monitoring tools may be using port 443. Identify the process : Open a command prompt as an administrator and run netstat -anob | findstr :443

. This will tell you the PID (Process ID) of the application occupying the port Workaround

: Stop the conflicting service during the Veeam upgrade. While Veeam Support

may suggest stopping it just for the installation, the VBR console may still fail to work later if the conflict returns Important Compatibility Notes Port is Hardcoded : In version 13.0.1.180 and newer, there is no supported method to change this port for the internal Veeam Web service Database Compatibility : Ensure your SQL database is at least SQL Server 2016

or newer, as v13 requires this compatibility level to function Firewall Rules

: Veeam usually creates its own firewall rules, but you must ensure no external network firewalls are blocking 443 communication between the backup server and its components PowerShell commands to identify exactly which process is holding that port?

Major Issues After Upgrading to Veeam V13: Port 443 Conflict 11 Dec 2025 —

Required Port 443 for Veeam Backup Replication is Occupied by Another Application: A Comprehensive Guide

Veeam Backup & Replication is a popular data backup and disaster recovery solution used by many organizations to protect their critical data. One of the key requirements for Veeam Backup & Replication to function properly is that it needs to communicate over specific ports, with port 443 being one of them. However, what happens when the required port 443 for Veeam Backup replication is occupied by another application? In this article, we will explore the issues that arise when port 443 is occupied, and provide a step-by-step guide on how to resolve this common problem.

Understanding Port 443 and Veeam Backup & Replication

Port 443 is the default port used for HTTPS (Hypertext Transfer Protocol Secure) communication. Veeam Backup & Replication uses this port to establish a secure connection between the backup server and the vCenter server or ESXi hosts for replication and backup operations. When Veeam Backup & Replication is configured to use port 443, it attempts to establish a secure connection to the target server. However, if another application is using port 443, the Veeam Backup & Replication job will fail.

Causes of Port 443 Occupation

There are several reasons why port 443 may be occupied by another application:

Symptoms of Port 443 Occupation

When port 443 is occupied by another application, Veeam Backup & Replication may exhibit the following symptoms:

Resolving Port 443 Occupation

To resolve the issue of port 443 being occupied by another application, follow these steps:

Step 1: Identify the Occupying Application

Step 2: Change the Occupying Application's Port

Step 3: Configure Veeam Backup & Replication to Use a Different Port

Step 4: Verify Veeam Backup & Replication Connectivity

Alternative Solutions

If changing the occupying application's port or configuring Veeam Backup & Replication to use a different port is not feasible, consider the following alternative solutions:

Conclusion

When the required port 443 for Veeam Backup replication is occupied by another application, it can cause significant disruptions to your backup and replication operations. By understanding the causes of port 443 occupation and following the steps outlined in this article, you can resolve the issue and ensure that your Veeam Backup & Replication jobs run smoothly. Additionally, consider implementing monitoring and logging to detect potential port conflicts and other issues before they impact your critical backup and replication operations.

Starting with Veeam Backup & Replication (VBR) v13, port 443 is a hardcoded requirement for the Veeam Web Service and API Gateway. If this port is occupied by another application, the VBR services will fail to bind and start. Identifying the Conflict

To identify which application is using port 443, run the following command in an elevated Command Prompt or PowerShell: Command: netstat -ano | findstr :443

This will return a Process ID (PID). You can then cross-reference this PID in Task Manager (under the "Details" tab) to find the specific application. Common Conflicting Applications

Hyper-V Replication: Often uses port 443 for its replication service.

VMware VirtualCenter Webservices: Standard vCenter components frequently listen on this port.

Web Servers: IIS or Apache instances running on the same machine. Solutions and Workarounds

Currently, there is no supported method to change the port for the Veeam Web Service in VBR v13. You must free the port by reconfiguring the conflicting application: For Hyper-V Conflicts: Navigate to Hyper-V Settings > Replication Configuration.

Change the specified port from 443 to a different, unused port.

Update the replica server port in the settings of each VM to match this new port. For Other Applications:

If the conflicting application allows port reconfiguration (e.g., changing the HTTPS binding in IIS), move it to a different port to allow Veeam to claim 443.

Temporary Bypass: Some users report disabling the conflicting service only during the Veeam upgrade, though the VBR console may still fail to work post-upgrade if 443 remains occupied.

Major Issues After Upgrading to Veeam V13: Port 443 Conflict

Starting with Veeam Backup & Replication v13, port 443 is a required and hardcoded port for the Veeam Web Service/API Gateway. This change often causes conflicts if the same server is already performing other roles, such as hosting a Hyper-V Replication server or another web application. Critical Conflict: Veeam v13 and Port 443

Hardcoded Requirement: In v13.0.1.180 and newer, port 443 is mandatory for the Web Service. Currently, there is no supported method to change this port within Veeam or bypass the installer's compatibility check.

Upgrade Block: If port 443 is occupied, the Veeam installer will typically block upgrades from v12 to v13 until the conflict is resolved.

Service Failure: If the upgrade completes but another application subsequently takes port 443, the Veeam Backup & Replication (VBR) services will fail to bind and may not start. How to Identify the Occupying Application

To find out which specific application is currently using port 443 on your Windows server, use one of the following methods:

PowerShell: Run the following command as an Administrator:Get-Process -Id (Get-NetTCPConnection -LocalPort 443).OwningProcess

Command Prompt: Use the netstat command to see all active ports and the associated Process ID (PID):netstat -ano | findstr :443 Common Solutions and Workarounds

Since Veeam's use of 443 is hardcoded, you must typically reconfigure the other application to free up the port: Reconfigure Hyper-V Replication:

If your VBR server is also a Hyper-V host, change the replication port. Go to Hyper-V Settings > Replication Configuration and change the port from 443 to a different value.

Update the Replica server Port in each VM's replication settings to match the new port to avoid re-replicating data. Stop and Disable Conflicting Services:

Identify the service (e.g., IIS, Apache, or a third-party agent) and stop it during the Veeam upgrade. If that service is non-essential, consider moving it to a different server. Temporary Release for Upgrade:

Some users have successfully completed the upgrade by temporarily stopping the conflicting application to let Veeam claim the port first. However, if the other application restarts and takes the port back, Veeam services may fail. Use a Dedicated Backup Server:

Best practice is to keep the VBR server on a dedicated machine or a workgroup-joined VM to avoid port conflicts and improve security against ransomware. Veeam B&R 13 Change Web Service Port 443 Before diving into solutions, it is critical to