prevent user login on 7.0 m020 with load balancer

Hi

Does anyone know how to prevent user login to Windchill system?

I need to do some maintenance clean up in a production server and I would like to prevent users from logging in.

I was thinking that maybe we could use ldap to place the production system in a test domain and then assign logins to the IT staff from within the test domain.

Thanks for any advice!

Cheers

Pat