Connect from cable modem directly to hub/switch?

[Relztrah]

I was looking through my Motorola Surfboard cable modem user guide and it shows a diagram of how to set up a (wired) network. There is no router; the diagram just shows a crossover cable going from the modem to a hub or switch and from there branching out to individual PCs. I never saw this configuration before, and have always thought you needed a router between your modem and hub/switch or PC. What am I missing?

[PrntRhd]

A home router is also a switch.
I recommend using a router for ease of connection plus the hardware firewall makes all the PCs more secure.
(It takes care of assigning the PCs addresses)

You plug the cable from the modem into the WAN port on the home router, and the PCs into the other ports in the router. Power on the modem, then the router, and then the PCs.

[Relztrah]

Ok, if a router is a switch, is a switch a router? I just bought a Linksys EZXS55W 10/100 5-Port Workgroup Switch in order to expand my home network. (I already have a router but I've maxed out the ports.) Can I use this switch as a router elsewhere?

[mjc]

Routers are more like 'smart' switches...

http://en.wikipedia.org/wiki/Router

http://en.wikipedia.org/wiki/Residential_gateway

[Variable]

If you read a networking book you will read about hubs, bridges, routers, switches and modems. These definitions don't apply to many home based devices anymore. You can buy a device that has all of the above devices features. A switch is a group of Ethernet ports that can be segmented. Imagine you have a one main cold water pipe in your basement, one end has a box that connects to water main coming from the city to a pipe coming in to your basement, the box steps down pressure and converts the water main pipe to a pipe in your home. This is akin to a network bridge, it changes the high pressure big pipe from the city to a low pressure PVC pipe in your basement.

From that connection you have one pipe stretching the length of your home. At various points along this pipe, your kitchen and bathrooms cold water lines connect to this pipe in your basement. All of the faucets with cold water in your house share this one pipe. This is a akin to a network hub. A network switch can be thought of using the same analogy, but each faucet that needs cold water has their own pipe going directly to the box connecting your home to the main water pipe coming from the city.

A router routes, so using the same analogy, imagine you expand your view and take in your neighbors home. They have the same set up as you do, but in front of both your homes is another large high pressure pipe filled with water for all the homes in your neighborhood, your house and your neighbors house, connect to this pipe to get water. Imagine there was a valve or valves, along this pipe that allows the water company to direct more/less water to individual homes based on your needs. Thats what a router would do, it directs packets (water) between different networks. This analogy only describes half of the network. You would have to add the sewer pipe to the equation to describe sending and receiving packets. But suffice to say it describes the basic concepts. You would duplicate the above network for sending packets (waste water) to the sewer mains.

Switches and hubs connect your network together, a router routes packets between different networks and a bridge connects dissimilar networks. You can use two routers in your own network. But what you would do is create two networks instead of one network. Networks are separated by their subnet mask. So if you had one router with a LAN side of 192.168.1.1 with a 255.255.255.0 mask your network would be 192.168.1.1 - 192.168.1.255. The last 0 in the subnet mask says "your network 192.168.1 and the available range for devices is 1-255.

Now assume you add a second router. This routers WAN side would be on the same network as your first router, say it was 192.168.1.100. The LAN side of the second router would be a different network. You could make the second router 192.168.2.1 with a mask of 255.255.255.0. So your second network would be 192.168.2.1 - 192.168.2.255. The last 0 in the subnet mask says "your network 192.168.2 and the available range for devices is 1-255."

Different home router manufacturers sometimes use different default LAN addresses. So sometimes you buy a Linksys router and plug it in to your cable/dsl modem and it works out of the box, you buy a Netgear router and plug it in to your Linksys and it works fine out of the box. This is because the LAN sides are different networks. If you bought two Linksys routers they both would probably have the same default LAN side. In that case you would have to change the second router yourself.


V

[Relztrah]

Thanks for the explanation. I gather from these replies and what I read on Wikipedia that I cannot use my Linksys EZXS55W 10/100 5-Port Workgroup Switch as a router so I won't attempt to do so.