SharePoint disable loopback check (DisableLoopbackCheck dword in registry)

Ive found this very handy.. recently, I was working on a server and we were trying to access the local SharePoint site http://127.0.0.1 or http://nameoflocalserver/pages/default.aspx and I was constantly prompted for the username and password. In SharePoint 2010, it can really annoy you by not accepting your username password credentials in the popup window.

Its a ‘feature’ on the server that you need to disable as a workaround (if you are an Admin/Developer) on a DEVELOPMENT and PREPROD environment.
Caution: Microsoft Best practices is out of scope in this article. Do your own research on this topic.

There are two methods to do this:
1.  Specify the host names in the registry – BackConnectionHostNames (more secure and recommended for PRODUCTION servers). Refer http://support.microsoft.com/kb/896861
2. Disable the loopback check – DisableLoopbackCheck (less secure and recommended for DEVELOPMENT environments). Read on to use this method 2 and add via an easy powershell cmd.

You would need to create a DWORD registry key in the registry called DisableLoopbackCheck and set it to 1.
Follow these steps:

Option 1: Add this registry entry by PowerShell

New-ItemProperty HKLM:\System\CurrentControlSet\Control\Lsa -Name "DisableLoopbackCheck" -value "1" -PropertyType dword

Option 2: Add this registry entry manually

Click Start, click Run, type regedit, and then click OK
In Registry Editor, locate the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
Right-click Lsa, point to New, and then click DWORD Value. (In Win 2008, its DWORD 32bit)
Type DisableLoopbackCheck, and then press ENTER.
Right-click DisableLoopbackCheck, and then click Modify.
In the Value data box, type 1 and then click OK.
Quit Registry Editor.
You may need to restart your server.

For more information about this, click the following article number to view the article in the Microsoft Knowledge Base: 281308 (http://support.microsoft.com/kb/281308/ ) Connecting to SMB share on a Windows 2000-based computer or a Windows Server 2003-based computer may not work with an alias name.

15 thoughts on “SharePoint disable loopback check (DisableLoopbackCheck dword in registry)

  1. The way of doing this is in production is to use method 1 as per Microsoft’s article http://support.microsoft.com/kb/896861
    However, I have had endless problems with getting method 2 to work. The solution for me was always to add the basic hostheader to the backconnectionhostnames reg key AND the FQDN i.e. hostheadername.domain.local (for example). I have foudn that a reboot is necessary, rather than just iisreset/noforce. Just using the basic hostheader name alone did not work.

  2. Thanks. Use this to solve my issues with search crawling sharepoint sites as well as opening sites in Designer.

  3. PLEASE SHOW READERS HOW TO PERFORM THIS PARAMETER CONFIG GIVEN CURRENT INFO:
    (if i dont use diable loopback=1 then this will break infopath forms)

    1. Authentication = NTLM

    2. Protocol = HTTPS

    3. Network Load Balancing = SharePoint Web Proxy – Fixed IP per WFE – TMG

    4. Server Adapter = DisableLoopBack on Entire Farm (Usually enabled for Crawl) – loopback attack taken care of by TMG

    5. SharePoint Forms = InfoPath 2010

    6. Data Connector V2 = UDC / UDCX (Change from Connector to File)

    a. Convert InfoPath Data Connector to Data File stored in SP Data Connection Library

    7. Data Connector Storage Configuration = Data Connection Library in SharePoint at Site Collection

    a. http://msdn.microsoft.com/en-us/library/ms772101.aspx

    8. Data Connection Authentication

    a. http://msdn.microsoft.com/en-us/library/ms771995.aspx

    9. Alternate Access Mappings

    a. External / Internal access need to be tested

    10. InfoPath Form Storage Location

    a. Must be stored in the site collection where its data file is being accessed

    11. Central Administration InfoPath Changes

    a. Web Service Proxy = Enabled

    b. InfoPath Form Services Configuration in Central Administration

    thanks for the effort .
    -mark

  4. Thank youuuu ,the first solution not worked for me but the second about DisableLoopbackCheck worked , thak you so much !!!!!!!!

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