I want to set up a this services dhcp, dns and active directory server on a computer which I have built I have purchased widows server 2012 RC2 and installed it.

The router is a Draytek vigor 2830n and has three WAN's

The broadband connection is connected to WAN1 so if I connect the above computer to WAN2 and WAN2 has no DHCP or DNS running on it can I use this WAN connection to run the above computer with the other windows client computers connected through the WAN1 connection not being affected, in order for me to migrate the users one by one and use the test windows client box, before I change the whole network?

Please advice :?:

OK, you mean Windows Server 2012 R2, not RC2 (RC2 doesn't exists, and if it did, the meaning would not be what you expect!).

You can't usefully connect any computer to WAN2 on the 2830n. They all have to be connected LAN-side. The VLAN facility of the 2830n may well be of some use to you, though. You can use it to create co-existing, but un-connected, LAN segments behind the router and put the WS2012R2in its own VLAN (with no 2830n DHCP/DNS on the server's VLAN) while you are getting it up and running. It will then have access to the Internet as will your existing workstations on another VLAN, but they won't be able to talk to/interfere with each other.

If you plan on migrating workstations into the AD domain piece-meal, you will also either need to connect them all wirelessly and migrate them between different WLANs (on the two VLANs) as needed, or you will need one or two LAN switches to connect the 2830n to its two sets of machines. That said, your post suggests you have a lot to learn about the networking and server concepts involved, so I genuinely wish you luck and fun with that.

Thank you for the information, been side tracked with other work so will look at setting that up I have a spare machine to connect to the server to get it sorted and then once I know that is okay get the rest over to the new network one by one.