Trust between two domain controllers on the same network

[adyamg]

I am new at this so please give me some advice.
We have 2 organization on the same ip class(192.168.0.x)
We have a domain controller that is used to manage computers from first organization, called server1
Second organization doesnt have a DC yet, but computers from second organization access resources from the first organization(a sql database). Second organization uses the ip adresses from 192.168.0.100-192.168.0.140

Now I would like to add server2 as a domain controller to manage comuters for second organization.I have installed a server 2008 R2, added Routing and Remote Access Service (RRAS) and setup the server to work as a NAT ROUTER(second org has a different ISP). My server2 has the LAN NIC set to 192.168.0.101
255.255.255.0
No GW, No DNS
The WAN NIC is setup to my ISP requirements and works fine.

The problem comes from the fact that computers from my second organization, after beeing added to my new domain cannot access resources from server1(SQL database) but the resources are accessible from server2 (192.168.0.101). Computers from second org can access computers from first org, but server1(witch holds DC and SQL) is not accessible
The NICs from second organizations are setup like 192.168.0.102-40
255.255.255.0
GW 192.168.0.101
DNS. my ISP DNS

I really hope I have made myself clear :)
Thanks

[SUpER CoP]

I think that you will need to have a 2 way trust if they are different domains and you need to access resources from either side. You can also try to create a user account in the other domain for the users connecting to it and configure the permissions on the folder for them as you need. Theroetical you can also open the folders for everyone but that i would avoid.