Yep, I am thinking that it may be what your default gateways are set to be as well
But you would most likely be better served by getting a hub to connect the two nets together, I don't know how many nodes (clients) you have on each of the nets, but if they all go out with the same static ip I would reckon that there is some NAT going on somewhere
Also, I don't know how many ports each of the routers has, but Check out this diagram for what your networks each probably look like on their own, is this correct? (I am thinking that you don't have the hubs and plug directly into the routers themselve, they prob have 4 or so ports in the back of each one; you may just be able to set up a vpn throught the net between each router and network too - check here for more info on that **
http://www.homenethelp.com/vpn/ ) :
Hope this helps some
/JD
Hybrid Mode
