401 UNAUTHORIZED with anonymous access: SharePoint 2010

One more new query from end user so here it comes my new article! Not query but actually an issue which requires some troubleshooting and correct guidelines to proceed for the resolution. One thing we need to understand that every issue requires thorough analysis and based on those analysis points, we can resolve the issue. By means of writing such articles, I would like to guide my SP-communities, SP audiences, my SP-friends / my colleagues, SharePoint Administrators- a proper set of guidelines so that they can resolve the issue and in case of any problems then please reach out to me so that we can discuss on the same and proceed further!

Farm attributes:-

-2WFE’s, 1 APP, 2 SQL instances in clustering mode

-SharePoint 2013

-Windows Server 2008 R2

-IE10

Problem description:-

I have created an anonymous site in SharePoint 2010 foundation and when i click on sign in, it shows me "401 UNAUTHORIZED". The machine is on a hosted environment and I am accessing it through a host header in extranet zone of alternate access mapping path.

Error message:-

401 UNAUTHORIZED

Troubleshooting steps:-

1)   As the site is anonymous then it does not have to ask for credentials. Make sure that's not the case.

2)   Make sure that you have already followed all the guidelines as how to setup the anonymous site across the complete site collection plus list and libraries.

3)   It might be browser specific so make sure that you test this scenario across multiple browsers

4)   As this is an extranet site, so obviously customizations are there on the home page as well. If that is the case then make sure the page is not check out. If yes then please approve it and check the results

5)   In most of the anonymous cases, one most common issue happens i.e. If the web part present on the home page need to query data from other list while anonymous user has no permission to access those lists, then maybe you would get the problem.

In my case, this is the resolution:-

1)   It was a webpart causing the problem.

2)   Present on the home page which requires permissions to access that specific list as it is fetching data from the external list.

3)   Removed the webpart

4)   Checked the results and works like a charm!

Product applies to:-

1.   SharePoint Server 2013

2.   SharePoint foundation 2013

3.   SharePoint server 2010

4.   SharePoint foundation 2010