Required Port 443 For Veeam Backup Replication Is Occupied By Another Application Link May 2026
SSRS is a notorious port 443 hog. Even if you stop the service, the URL reservation persists.
If you are installing or upgrading Veeam Backup & Replication (VBR), encountering the error "Required port 443 for Veeam Backup & Replication is occupied by another application" is a common, albeit frustrating, roadblock.
Port 443 is the standard port for HTTPS traffic. Because it is the default secure port for the web, many applications (IIS, Skype for Business, VMware Update Manager, and various web servers) fight for control over it. Veeam requires this port for its internal web server to communicate with the console, mount servers, and manage the backup infrastructure.
This article explores how to identify the culprit and resolve the conflict without compromising your network security.
The error "Required port 443 for Veeam Backup & Replication is occupied by another application" is rarely a sign of Veeam being broken; rather, it highlights a classic Windows port contention issue. By methodically identifying the process using netstat, removing HTTP.SYS reservations, reconfiguring IIS or SSRS, or changing Veeam’s own port, you can resolve the conflict in under 15 minutes.
Remember, port 443 is prime real estate. Decide which application—Veeam or the existing service—is more critical for your environment, then adjust accordingly. With the steps above, you’ll have Veeam Backup & Replication listening securely and ready to protect your data.
Need further assistance? Visit the official Veeam R&D Forums or open a support case with Veeam Customer Support. Include the output of veeamportssniffer.exe (available in the Veeam ISO tools folder) for rapid troubleshooting.
Depending on what you find, take the appropriate action:
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:
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.
In 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 during installation or upgrade, the Veeam services will fail to bind and start. Identifying the Conflicting Application
Before resolving the conflict, identify which process is currently using port 443. SSRS is a notorious port 443 hog
Command Prompt: Open CMD as Administrator and run:netstat -anob | findstr :443
PowerShell: Use this command to find the specific process name:Get-Process -Id (Get-NetTCPConnection -LocalPort 443).OwningProcess Common Applications Causing Conflicts
Hyper-V Replication: If the VBR server also acts as a Hyper-V Replica server, it may already be using 443 for HTTPS replication.
IIS (Internet Information Services): Web servers hosted on the same machine often default to 443 for HTTPS.
VMware vCenter/ESXi: If VBR is installed on a machine with other management tools, they may occupy the port. Resolution Steps
Because port 443 is currently hardcoded and cannot be changed within Veeam v13 settings, you must reconfigure the conflicting application. Option 1: Reconfigure Hyper-V Replication (If Applicable) If Hyper-V is the culprit, change its replication port: Go to Hyper-V Settings > Replication Configuration.
Change the Specify the Port value from 443 to a different port (e.g., 444).
Update the replication settings for each individual VM on the host to match the new port. Option 2: Temporary Service Suspension If the conflicting application is only needed occasionally:
Stop the conflicting service (e.g., IIS or a custom web app). Complete the Veeam VBR v13 upgrade or installation.
Attempt to restart the original service on a different port if possible. Option 3: Use a Dedicated Backup Server
Veeam best practices recommend installing VBR on a dedicated server to avoid resource and port conflicts. If port 443 is essential for a primary line-of-business application on that server, migrating Veeam to a separate VM or physical host is the most stable long-term solution.
For deeper connectivity troubleshooting, you can refer to the Veeam Ports Finder Tool to map out all required communications. The error "Required port 443 for Veeam Backup
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: Need further assistance
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
Here’s a properly worded version of your message:
"Port 443, required for Veeam Backup & Replication, is occupied by another application."
If you want to keep it closer to your original structure:
"Port 443, which is required for Veeam Backup & Replication, is currently occupied by another application."
Or more concisely (e.g., for an alert or log message):
"Required port 443 for Veeam Backup & Replication is in use by another application."
After freeing port 443:
netstat -ano | findstr :443
Example output:
TCP 0.0.0.0:443 0.0.0.0:0 LISTENING 1234
The number 1234 is the Process ID (PID).
