I am faced with a problem for which I need your help.
We have a 3 server SharePoint 2010 farm – 1 WFE, 1 Application and 1 Database Server.
I have configured my SharePoint site to work with Forms Authentication, the authentication is done against an LDAP directory. The specifics of the Forms Authentication have been taken from an already existing SharePoint 2007 farm, where the authentication is working perfectly fine.
I have also set the same authentication mechanism for my development farm, however the dev farm contains 1 SharePoint Server and 1 Database Server.
Coming back to my production environment, I have set the Forms Authentication as with the other 2 farms and I am successfully able to authenticate myself using the default URL.
However, I had to configure an Alternate URL for my site. I used Alternate Access Mapping to configure the new URL for the site. Here I was unable to use the Forms Authentication, the error states that the credentials are incorrect.
I found an error in the ULS logs that the Security Token could not be issued for the user as the user name and password were not identified.
Next, I do an IISRESET and the error is gone. I am able to successfully login to the same site with the same credentials. This does not stop here.
Next day, I am again faced with the same error and again everything starts working fine after an IISRESET. This has been going on for a number of days now.
I had tried certain solutions like making modification to the Membership Provider in the web.config but these seem pretty useless as the same details of Membership Provider are working in the other 2 farms.
Please share any ideas or thoughts you might have regarding this issue.