So i've successfully upgraded from 4.2.1 to 4.5, but i'm not sure how to get LDAP authentication up and working.

I've entered in all the following settings for my ldap domain info on the admin->systemsettings->ldap page

domain.local
DC=domain,DC=local
userPrincipalName
userPrincipalName
CN=webuser,OU=nonhumanusers,OU=Resouces,OU=Corpora te,OU=corp,DC=domain,DC=local
<pass for webuser>
<auto create unchecked>

So I have a number of existing users on the system, i'm wondering how to get them to be LDAP authenticated? Am i missing something?