Windows Server Update Services (WSUS) gets synchronized with Microsoft Update or an upstream WSUS server in the following manner:
1. **WSUS Server Configuration**: The WSUS server is initially configured with the necessary settings, including the synchronization source and schedule. Administrators can choose to synchronize directly with Microsoft Update or with another upstream WSUS server within the organization.
2. **Synchronization Schedule**: Administrators set up a synchronization schedule based on their organization's needs. This schedule determines how often the WSUS server checks for new updates and synchronization.
3. **Synchronization Source**:
- **Direct Synchronization with Microsoft**: If the WSUS server is configured to synchronize directly with Microsoft Update, it connects to the Microsoft Update servers over the internet.
- **Upstream WSUS Server**: If the WSUS server is part of a hierarchy or downstream from another WSUS server, it can synchronize with the upstream WSUS server instead of connecting directly to Microsoft Update.
4. **Metadata Retrieval**: During synchronization, the WSUS server requests update metadata information from the synchronization source. This metadata includes details about available updates, such as their names, descriptions, classifications, and release dates.
5. **Metadata Comparison**: The WSUS server compares the received metadata with its existing database to identify new updates, updates that are no longer available, and updates that require approval.
6. **Downloading Update Files**: If new updates are detected, the WSUS server downloads the associated update files (also known as update binaries) from the synchronization source. These files are stored locally on the WSUS server.
7. **Database Update**: The WSUS database is updated with the newly synchronized metadata and the locations of the downloaded update files.
8. **Administrative Approval**: After synchronization, administrators can review the synchronized updates and approve or decline them based on their organization's needs and policies.
9. **Client Availability**: Approved updates are then made available to client computers that are configured to use the WSUS server for update management.
10. **Client Interaction**: Client computers configured to use WSUS will periodically check in with the WSUS server to determine which updates are needed for their systems.
11. **Deployment**: Administrators can schedule and control the deployment of updates to client computers, ensuring that updates are installed during maintenance windows or at other appropriate times.
By following this synchronization process, WSUS ensures that the WSUS server's database is up-to-date with information about available updates, allowing administrators to manage and deploy updates efficiently within their organization while conserving bandwidth by not repeatedly downloading the same update files.