Question : DHCP / DNS for multi-domain enviornment

Local office, 192.168.25.X address scheme
All DHCP clients are:
IP range: 192.168.25.100-150
NM: 255.255.255.0
GW: 102.168.25.254
DNS: 192.168.25.7 & 8
The local domain is new.com

new.com has Windows 2008 AD/Exchange/DNS/DHCP services in local office. When client PCs boot up, they receive DHCP settings without issue.

One problem... there is ANOTHER company in the building that owns a majority stake in new.com, named old.com. old.com is an entirely seperate domain and corporate structure. Old is slowly migrating servers to the local office, but currently all servers reside in a remote location. That remote location has Windows 2003 AD/DHCP/DNS/Exchange. It's address scheme is 192.168.1.X.

old.com and new.com have an MPLS WAN which takes care of all the routing (We have an MPLS cloud that handles all traffic routing for 8 seperate offices). We have no issues with adding computers/users/printers to the old.com domain from the local office. However, as stated earlier, the DHCP scope in local office is setup for members of the new.com domain. Therefore, it has new.com DNS entries. (i.e. 192.168.25.7 and 192.168.25.8) When I add a old.com computer to the local office, I set to "Obtain IP address automatically" but I have to hardcode the dns settings to 192.168.1.7 & 8. This creates problems for laptop users (users do not have local admin rights) of old.com. Old.com laptop users require a hardcoded DNS entry, but I have to remember to change it before they leave the office. Otherwise, they will have hardcoded DNS local DNS entries, and therefore they cant use the internet at home.

What kind of solutions are available?

1 - Can you setup seperate dhcp scopes for old.com and new.com in the local office? (I imagine this is impossible)

2 - Is there a way to properly forward the dns traffic bould for old.com from the local office which has only new.com dns/ad?

*note - I have full admin privledges for both domains*

Answer : DHCP / DNS for multi-domain enviornment

Delete any existing zone you have for old.com on the new.com servers. Add a conditional forwarder, or secondary zone for old.com to the new.com servers.

That's all you should have to do...

Chris