6.1 Switching

Welcome to a session about home gateways. In this session you will see that a home gateway carries out several different tasks. On a managed network in a business context, these might be carried out on several different devices; a home gateway won’t be as fast or powerful as these, but it is quite a sophisticated device.

I’ll start with something simple – a new network with a gateway router, a desktop, laptop and tablet, and I’m going to use wired connections first.

Initially I’m going to set up static IP addresses manually. What addresses should I use? It’s best to stick to the private address range because you won’t be popular if your IP address conflicts with Google or Facebook – or maybe you’ll be very popular.

So I’m going to set my desktop to IP 192.168.0.10 and my laptop to 192.168.0.20.

Now I can connect them to the router with Ethernet cables. So from the Ethernet port to the first free Ethernet port on the gateway, and then from this Ethernet port to the next free Ethernet port on the gateway.

So let’s see if I can ping between machines. I’ll type ipconfig to check my own IP address, and then ping 192.168.0.20, the address I set for my laptop. And there are some return pings, so I do have a network connection.

The gateway here is operating as a switch, nothing else. It learns which machines are connected and will pass packets to the correct destination.

The gateway router itself is a device on the network and it has its own IP address. But what is it?

With luck, the gateway will have set itself up with a default IP address that is well known and documented in the manual. Here I know it is 192.168.0.1 and I should be able to ping from my desktop to confirm that the router is responding. And there we are.

So we have a local network set up, and the gateway is acting as a switch transferring data between devices within the LAN.