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

Critical Error: "Required Port 443 for Veeam Backup & Replication is Occupied by Another Application" – Causes and Fixes

Introduction

Veeam Backup & Replication is widely regarded as the gold standard for data protection in virtual, physical, and cloud environments. However, even the most robust platforms can encounter installation or upgrade issues. One of the most frustrating and frequently reported errors during Veeam deployment or service restart is:

Internet Information Services (IIS): Often installed on Windows Servers, hosting default websites on HTTPS. Critical Error: "Required Port 443 for Veeam Backup

  • API endpoints to programmatically query and set networking ports for automation/orchestration.

    • : VBR v13 introduces a REST-based web service that handles core management tasks and the modern Web UI. Identity Service API endpoints to programmatically query and set networking

    1. Open Server Manager -> Tools -> Internet Information Services (IIS) Manager.
    2. Expand the Server -> Sites.
    3. Right-click the site using port 443 (usually "Default Web Site").
    4. Select Edit Bindings.
    5. Select the https binding on port 443 and click Edit.
    6. Change the Port to a non-conflicting port (e.g., 8443 or 444).
    7. Restart the Veeam Backup Service.

    If you are not using IIS on this server: : VBR v13 introduces a REST-based web service

    Hyper-V Replication: If your backup server also acts as a Hyper-V replica host, it likely uses 443 for replication traffic.

    Case A – Unnecessary application (e.g., Skype, Teams):