Get 2 IP Ranges to talk to each other

[m8rk]

I'd appreciate your guidance on what's the best way to have things setup.

1 x Windows2000 AD PDC DHCP DNS Server [soon to be migrated to 2003]. 2 file servers - one each for two groups of users.

I have 2 IP ranges to cater for the volume of devices on site. The router is out of my control on a 10Mbit fibre a mile away across town, and the local council [we're on their WAN] have just enabled the two ranges to talk across it.

The two ranges are: 172.16.57.x & 172.15.140.x

I can't see machines in the other range without having two network cards - on in each range - setup on the target machine. My servers all have 2 network cards as well, including the domain controller. The IP's of the servers have the same last 3 digits