Quick Friday tutorial! Seems there’s a lot of confusion over the various ‘Download Mode’ settings in Delivery Optimization Group Policy. This the more detailed version of the settings that are exposed via the UI in the Windows Update settings. So we made a simple reference table for you, as we are in a giving and sharing mood today.
We blogged about the DO policies in more detail here and here, but this just refers to what is probably the most important setting, which determines how the DO service performs its downloads, when it may or may not use peers etc..
Note also that defaults vary between Windows SKU – Pro/Ent
For more Microsoft info on Delivery Optimization – start here. Have a nice weekend, and don’t get your DO in a twist…
Microsoft Delivery Optimization Service ‘Download Mode’ Policy Settings And Behaviour
|Mode and Value||Peering
(Get Content From Peers)
(Share content with Peers)
|0=HTTP only, no peering.
|No||No||Disables peer-to-peer caching but still allows Delivery Optimization to download content from Windows Update servers or WSUS servers.|
|1=HTTP blended with peering behind the same NAT.||Yes||Yes||Delivery Optimization cloud service finds other clients that connect to the Internet using the same public IP as the target client (NAT).|
|2=HTTP blended with peering across a private group.||Yes||Yes||Only seeding/peering from same group ID
Peering occurs on devices in the same Active Directory Site (if exist) or the same domain by default. When this option is selected, peering will cross NATs. To create a custom group use Group ID in combination with Mode 2.
|3=HTTP blended with Internet Peering.||Yes||Yes||Seeding and Peering everywhere. Default for the Window Pro SKU|
|99=Simple download mode with no peering.||No||No||HTTP Only from source.Delivery Optimization downloads using HTTP only and does not attempt to contact the Delivery Optimization cloud services.|
|100=Bypass mode. Do not use Delivery Optimization and use BITS instead.||No (Unless BranchCache is enabled and WSUS is in play)||No (Unless BranchCache is enabled and WSUS is used)||BITS and BranchCache will be used instead.|