We have 2 DC in our main site and one DC off site doe Disaster
recovery
purposes. I only want users to authenticate to our 2 main
DC's only and for
them to replicate at night only to this offsite DC, how can I
do this?
you could also configure the DC not to register the domain-wide and
the site wide DNS service records and only register its name and IP
and the CNAME record for registration purposes. As Tomasz said, it
works best to put it into its own site. When doing that it is not
needed to put the DC in its own subnet.
* Create an additional site
* Create an additional site link and put the main site and the new
site in it and configure replication cost and schedules accordingly
* Create a 32bits subnet containing the IP address of the DC and a
subnet mask of 255.255.255.255
* Link the subnet to the new site
* move the DC to the new site
* Use a GPO on the new site so the DC does not register the records as
said earlier
* Cleanup DNS records of the DC in DNS in the old site (otherwise
clients might still authenticate to it)
* Do not assign WINS IP addresses to the DC in the new site otherwise
clients (legacy) might find the DC through WINS (1Ch record that
contains all DCs)