> "Upgrade" a network? "Extend" a network? > I have no context whatsoever to work with. Thanks for replay Bryan. Excuse me for my low knowledge level. I'll try to explain it. Imagine you need to give service(mail, web, browsing etc.) to different institutions. Some institution connect using commuted lines and others directly through the main ISP router. The location of the node where all the servers and the main local router are, is inside one of these institutions. In this moment, the network of the node have a subneted C class range and the local institution (where is the node place) is connected using a PC with 2 interfaces that connects both networks. At this time all is working, but new workstations are planed to arrive and we need to increase the number of stations in the local institution, so 254 PCs actually are not enough. So we are looking a way to extend or increase the number of possibles workstation. I proposed the idea of create various networks and separate the local institutional services from the node, to make them independent one of another. So, connected to the main local router will be a switch, this will be the top level local switch where the node and the local institution will be. The node is formed by various servers that will be connected directly to the switch. The main objective of the node is to administer mail accounts and RADIUS service (don't know it at all) and control browsing for the users connected. The institution is formed by a PC with various eth interfaces, one to connect to the router, and a serie of 192.168.1-2-3-...n.0 that permit us to connect 254 workstation for each one. Maybe will be needed more than 1 box here, think that the number of eth interfaces in a PC is limited. The main objective here are browsing, mail and web publishing. That's it, don't know if I explain my self. Don't know if my idea is correct, just an idea of what I've been reading on Douglas E. Comer TCP/IP (my first reading about networks). Again, thanks Bryan for replaying. Any suggestion or idea of how make this will be strongly appreciated.