Firewall/NAT

I apologize if this is posted in the wrong section. 

Setup:
 - I have a network that has two locations: building A and B. 
 - The internet comes in to A.
 - m0n0wall is the firewall in A.

Problem:
I have three internal networks that must be separated out in each building. x.x.8.x, x.x.9.x, x.x.10.x. I have one fiber connection coming into B from A.  I thought I would use a second m0n0wall in B and send all the traffic from the fiber into the WAN connection and separate the traffic out there.  However, the traffic on WAN in B, is all internal traffic. 

Is this configuration possible? If so, could give me some hints as to anything unusual in the configuration of this setup?

Thank you in advance for your time.

I'd use VLAN's, assuming you have managed switches, and trunk them across the fiber. Set m0n0wall's LAN port to a trunk port, and configure the VLAN's appropriately on it.

I'd use VLAN's, assuming you have managed switches, and trunk them across the fiber. Set m0n0wall's LAN port to a trunk port, and configure the VLAN's appropriately on it.

I considered VLANs. We have two Cisco 2950 switches but don't have the expertise to program them for VLAN use. Furthermore, our campus computing services isn't interested in helping since this is an  additional network on campus that they don't control. I am trying to achieve the same results with two m0n0wall systems.

VLAN config is simple, and is the only good way to do this. If you google "Cisco 2950 VLAN" you'll find all kinds of info.

Unless you have a dedicated switch for each subnet, and a dedicated switch for each side of the fiber, you can't use m0n0wall to do the same thing without the use of VLAN's. You still need m0n0wall to route between the VLAN's.

VLAN config is simple, and is the only good way to do this. If you google "Cisco 2950 VLAN" you'll find all kinds of info.

Unless you have a dedicated switch for each subnet, and a dedicated switch for each side of the fiber, you can't use m0n0wall to do the same thing without the use of VLAN's. You still need m0n0wall to route between the VLAN's.

I have a dedicated switch for each network on each side of the fiber. 

When I looked up setting up a VLAN using google, we got instructions and we set it up the way the instructions told us to.  However, the broadcast that was supposed to happen failed and I am not sure why.  Is there a site you recommend for setting up a VLAN?

Thank you for all your information.

I actually just setup a VLAN on a cisco 2960 a few weeks ago using elinks accessing the cisco website!! :-)

Here's similar instructions for the 2950:

http://www.cisco.com/en/US/docs/switches/lan/catalyst2950/software/release/12.1_9_ea1/configuration/guide/swvlan.html

The cisco website is the best resource I've found for their switches. Go figure.