How to restrict some selected CHILD Domains in the entire AD forest ?

HI OF Team,

We have an OF server hosted on Centos (linux) and is AD authenticated. I am succefully able to allow users from CHILD domains onto my OPENFIRE box which is hosted on Parent Domain (Global Catalog Server) using the below discussion.

http://community.igniterealtime.org/message/123488

Now, my requirement is to stop/block/restrict all users on a specific Child domain. Can i acheive this from OPENFIRE Server end ? rather than blocking 5222 port in their network VLAN.

Thanks & Regards,

Adhiraju Mouli