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Branchcache - main office offline ; will files be accessible to branch? RRS feed

  • Question

  • I would like to know, in the event that the main office is down? Will the clients still have access to the files being cached or will it be inaccessible as well?

    Is there a threshold can be set to declare that the main is offline and disconnect the clients from caching files from the server?

    Wednesday, July 3, 2019 9:19 AM

All replies

  • Hi,

     

    For your first question, as we know BranchCache operates in one of two modes:

     

    Distributed cache mode  In this mode, branch office client computers download content from the content servers in the main office and then cache the content for other computers in the same branch office. Distributed cache mode does not require a server computer in the branch office.

    Hosted cache mode In this mode, branch office client computers download content from the content servers in the main office, and a hosted cache server retrieves the content from the clients. The hosted cache server then caches the content for other client computers.

     

    Both Modes required response from main office when first time clients requested content from content server in main office. So I suppose, users could not load cache files when main office is offline for first time.

     

    And for second one, I did not find anything related to this when searching internally.

     

    Hope this clarifies.

     

    Thanks,

    Jenny


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    Thursday, July 4, 2019 6:48 AM
  • Hi,

    Just checking in to see if the information provided was helpful.

    Please let us know if you would like further assistance.

     

    Thanks,

    Jenny


    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Friday, July 5, 2019 3:17 AM
  • Both Modes required response from main office when first time clients requested content from content server in main office. So I suppose, users could not load cache files when main office is offline for first time.

    How about when the file(s) were accessed already then the main office hosting branchcache server goes down?

    Friday, July 5, 2019 7:29 AM
  • Hi,

    Per further searching, I'm afraid this is not workable as well. kindly check details as below.

     

    >>BranchCache is designed to prevent unauthorized access to content. Before transfer between peers or between clients and the hosted cache server, content is encrypted by BranchCache. Content can only be decrypted using the identifiers provided by the content server in the main office.

    https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/ee307962(v=ws.10)

     

    >> How Branch cache works

    • The server computer at the datacenter authenticates the user and verifies that the user is authorized to access the data.
    • The server computer at the datacenter returns identifiers (hashes) of the requested content to the client computer instead of sending the content itself. The server computer does so over the same channel that the content would have normally been sent.
    • Using the retrieved identifiers, the client computer does the following:

    If configured to use Distributed Cache, the client computer multicasts on the local network to find other client computers that have already downloaded the content.

    If configured to use Hosted Cache, the client computer looks up content availability on the Hosted Cache.

    https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-7/dd637784(v=ws.10)

     

    It seemed that clients need to retrieve identifiers from datacenter(main office) before looking for content in branch office, which also ensure the data security.

     

    Thanks,

    Jenny


    Monday, July 8, 2019 7:05 AM
  • Hi,

    I am checking to see how things are going there on this post.

     

    You can click “Mark as answer” if any of above reply is helpful. It would make this reply to the top and easier to be found for other people who has the similar problem.

     

    Best Regards,

    Jenny


    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Tuesday, July 9, 2019 1:34 AM