A. Most broadband routers on the market today are really a combination of a router and an Ethernet switch. The part of the router that the PCs connect to is the switch. It forms a local area network (LAN) of the computers connected to it. The router part of a broadband router/switch connects the PCs to the Internet via its WAN (Wide Area Network) port and its built-in NAT and DHCP server.

Because a broadband router/switch conceptually expands a single port on a MODEM to serve several PCs connected to it, there may be a tendency to think that another router is the way to expand a PC port on a broadband router to provide service to still more PCs. Such is not the case. PC ports on an Ethernet switch are usually expanded by ganging Ethernet switches; i.e., an Ethernet switch is the best way to add more PC ports to a broadband router. An Ethernet hub can be used as well.

In a pinch, many broadband routers can also be used to expand the PC ports on another router, but there can be configuration problems (and frustration) in trying to do so, it may not be as fast, and routers generally cost more than hubs and switches.

Connect the switch's uplink port to a PC port on the router with a straight-thru cable. If the switch does not have an uplink port, connect one of its PC ports to a PC port on the router with a crossover cable.

If you use a router to expand the PC ports on another router, connect one of the PC ports on the router to the PC port on the router connected to the MODEM with a crossover cable. If you gang the routers so they are connected together via the WAN port, be advised that WAN ports usually operate at 10 Mbps instead of the 100 Mbps that PC ports operate at. Also, disable the built-in NAT and DHCP server on the router furthest from the MODEM. That essentially configures the router to be a switch.