Two Domains, one network

graeme_jenkins used Ask the Experts™
Hi All,

I'm sure this is an easy problem for you...

I am creating a new training suite in our office which needs to be completely seperate from our current domain.  It will have a new server and PCs, all running by itself with no cross-over between it and the existing domain.  This is the easy part (I think).  

I need to use the existing company network wiring to connect these machines/server to the internet via the existing router (no proxy).  This is the only thing they need to share.

My Question then;

Can I just setup a new server (for AD/DNS//Files), PCs (fixed IP) and hub for the new small (10 pc) network and plug it into the existing company network for internet, or am I going to bump into problems? and if so, what are the problems likely to be?

Thank you in advance for your help.
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Hi there,

you won't get any Problems besides the fact, that the new domain can be found in the explorer.
If you use the new domain for training of external peaople and do not want them to see the internal
computers and domain, then you must invest a greater effort to keep the two domains/network apart.

Will work fine - one thing that you probably want to make sure you do is create a stubzone on the primary domain's DNS servers to point to the new domain, and / or create DHCP reservations for all of the pc's to go onto the training network and configure the DNS settings to point to the DNS server on the training DC.
Ernie BeekSenior infrastructure engineer
Top Expert 2012
If possible, try to plug it directly in to the router so you can get on to the internet but not to the other network (requires some configuration on the router).
Or (if the hardware supports it) create an extra vlan on the existing network that connect the training network to the router so it can connect (requires some configuration on the switches and the router).
That way you can keep it completely separate.
Of course I don't know the details of your network so I can't go in to details as well.
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Jon ScrivenSenior IT Infrastructure Officer
Best practise (for performance reasons and simplification) would be to separate it onto a different subnet, but you would need a multi-homed device (more than one network card) or a switch that supports VLAN to do this properly so that common devices were accessible from both networks.

This link might help:-
Mike ThomasConsultant
Top Expert 2010
Just creat a vlan for the new domain/clients and the domains will never see each other but seeing each other will not cause you an issue.


Thank you for everyone's quick response!

As all the solutions were helpful in their own right I've split the points between all of you.

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