Hello HunteR,
my intsallation of Alfresco runs on a Windows Server, but i think it will work the same way on RedHat
here are the lines I added to "alfresco-global.properties":
authentication.chain=alfrescoNtlm1:alfrescoNtlm,ldap-ad1:ldap-ad
ldap.authentication.allowGuestLogin=false
ldap.authentication.userNameFormat=%s@[domainname] #this parameter allows you to log on with the simple user name (without @[domainname])
ldap.authentication.java.naming.provider.url=ldap://[hostname].[domainname]:389
ldap.authentication.defaultAdministratorUserNames=[ActiveDirectoryAdmin]
ldap.synchronization.java.naming.security.principal=[ActiveDirectoryAdmin]@[domainname]
ldap.synchronization.java.naming.security.credentials=[password]
ldap.synchronization.groupSearchBase=dc=[domainname],dc=[suffix]
ldap.synchronization.userSearchBase=cn=Alfresco Service,ou=Serviceuser,ou=Users,dc=[domainname],dc=[suffix]
if your domainname is "company.com" the groupSearchBase and userSearchbase parameter would be dc=company,dc=com
everywhere else I use [domainname] as "company.com"
with this configuration you are able to log on to Alfresco with your Active Directory credentials.
useraccounts will be created after first login.