This is how a client computer determines which distribution point (DP) to use.
Step | From | Action |
1 | Client | Sends a content location request to its Management Point (MP) |
2 | MP | The search for Distribution Points (DP’s), with the content, starts in the client’s current site. This can be the client’s assigned site, secondary site attached to it, or a site to which the client is roamed. When the content is not available here, the search goes to the assigned site. |
3 | MP | The list of Distribution Points will be sorted. When a protected DP is found, where the client’s boundary is included, only it will be returned. If there is no protected DP found, the MP will return a list of non-protected DP’s that host downloadable content. |
4 | MP | The remaining Distribution Points on the list will be marked as local, or remote, depending on the associated boundary. |
5 | MP | The Distribution Point list is sent back to the client. |
6 | Client | The client receives the Distribution Point list and then attempts to connect to DP’s in this order: local DP’s and then remote DP’s; same IP subnet, same AD site, and then the remaining DP’s. In every category, the client prefers DP’s with BITS enabled. |
Content source priority
When a client needs content, it makes a content location request to the management point. The management point returns a list of source locations that are valid for the requested content. This list varies depending upon the specific scenario, technologies in use, site design, boundary groups, and deployment settings. The following list contains all of the possible content source locations that a client can use, in the order in which it prioritizes them:
- The distribution point on the same computer as the client
- A peer source in the same network subnet
- A distribution point in the same network subnet
- A peer source in the same boundary group
- A distribution point in the current boundary group
- A distribution point in a neighbor boundary group configured for fallback
- A distribution point in the default site boundary group
- The Windows Update cloud service
- An internet-facing distribution point
- A cloud distribution point in Azure
Notes
https://docs.microsoft.com/en-us/sccm/core/plan-design/hierarchy/package-transfer-manager
https://docs.microsoft.com/en-us/sccm/core/plan-design/hierarchy/client-peer-cache