How to connect RHEL 6.7 to 2012 AD and login with AD Accounts??

I need to be able to login to RHEL 6.7 servers using Active Directory accounts from a Windows 2012 Domain.
I've seen some information on the web, but nothing has worked for me so far.
Has anyone accomplished this?
Would appreciate it if someone could share what worked for them or point me to some info that they used.
Thanks!