LDAP on LAMP not working but is on WIMP

[caperneoignis]

Okay, I'm new to getting LDAP working on lamp. I apologize if this is the wrong forum but I was unsure of where to post first since I'm not sure where the fail is coming in at. A little bit of the back story, we have a web application using LDAP for SSO. This feature works on the WIMP server, but not the LAMP server. They have the same settings on both web applications. The web application is the same version on PHP, MySQL and the LDAP server is the same Windows LDAP. Obviously the Windows machine is running IIS. But the LDAP Authentication is coming from PHP. The settings for the Authentication are copy and pasted from the WIMP server to the LAMP server. I have opened the port for LDAP on the firewalld service. Am I missing something? Is there a setting I need to worry about with SeLinux? Do I need to add the Linux server to the AD also? Any help in narrowing this issue down would be greatly appreciated. I just need some helpful advice in where to look, or even if this post would be better in another forum. I'm just trying to figure out where the break is happening, and why it seems like it wants to work but not. Is PHP call for LDAP different on the Linux side then the windows side? We are trying to migrate to Centos 7 just in case any one was wondering. Please let me know if you have any further questions.

Thank you,