Go back
Knowledge base

SharePoint, HTTP 401.1 and DisableLoopbackCheck

Sasa Popovic Categories: SharePoint Server Date 10-Jun-2010
Sharepoint, HTTP 401.1 And Disableloopbackcheck

Table of contents

    A colleague of mine setup a new WSS Virtual Machine a few days ago, made a website in WSS, configured it to work with a FQDN and when he tried to access the website using Internet Explorer, he got the annoying generic error message from his browser.

    We looked at IIS logs and saw one of quite common HTTP errors there. It was HTTP 401.1 again. I remembered of the most common cause of that error, made a workaround on my colleague's VM and thought it would be good to blog about it as it happened so many times to people I know.

    The error was generated because of a security feature (or security fix) called loopback security check. The feature is present in Windows Server 2003 SP1 and later (including Windows Server 2008).

    I will not write here about how to work around this problem because it was already explained in detail in the following KB article: http://support.microsoft.com/kb/896861.

    A nice explanation about loopback check and effects it can have on your WSS or MOSS installation can be found here: http://www.harbar.net/archive/2009/07/02/disableloopbackcheck-amp-sharepoint-what-every-admin-and-developer-should-know.aspx

    sas-a-popovic-_authorsphoto.png
    Sasa Popovic Partner and CEO

    Strategic. Creative. Practical. Sasa is the supervisor for every project that the company takes on.
    More Posts from the Author:
    2023 annual review: The year of financial stability and investment
    Hiring for Humility: The Secret Ingredient to Exceptional and High-Performing Teams
    Is your company resilient enough for the times ahead?

    Latest blog posts

    Boris Bibic | 07-May-2024

    What is SRE and what is the role of SRE teams?

    SRE stands for Site Reliability Engineering and originats from Google, where it has spread all over the industry. The set of practices used in SRE are closely related to DevOps (mostly the Ops part), but with a focus on cre...

    Read more
    Tijana Đukić | 20-Jun-2023

    Intent classification: understanding text with the powe...

    In today’s world, with the expansion of data generated from various sources, analyzing it has become a critical challenge for businesses. Read more about how intent classification of textual data works and how it can lead t...

    Read more
    Aleksa Nikolić | 16-Jan-2023

    What Is Stable Diffusion and How Does It Work?

    For the past few years, revolutionary models in the field of AI image generators have appeared. Stable diffusion is a text-to-image model of Deep Learning published in 2022. Find out the reasons why Stable diffusion gained ...

    Read more