Hello lottsns,
I do not know if there is an existing visual - but I went ahead and threw this together quick to give you a basic understanding of how it works.
Image may be NSFW.
Clik here to view.
Image may be NSFW.
Clik here to view.
Image may be NSFW.
Clik here to view.
Commonly people also install PXE reps on their Preferred servers as well.
Note - if you have a DFS in your environment - you can also use that instead of using preferred servers for your packages.
Hope this helps to give you a basic overview visually.
-Peter
