Cable connection

Sunday, 3 December 2006, michuk

Cable connection is a popular one and it’s the easiest one to set up at the same type. For cable connection you need a cable modem — a device that connects a computer system to the Internet via the cable television network.

Setting up cable connection

It may be a surprise to you but usually you don’t need to do anything to set up cable connection. Just connect the network cable from your modem to your computer and wait. The connecting should be done automatically by GNU/Linux, which always tries to discover the DHCP connections by itself. If it does not work by itself, it may be that you have a messed up network configuration. The good thing is that you can easily check this and we’ll show you how.

If you are using GNOME, go to System->Administration->Networking. The system should ask you about your password and a small networking applet should show up (see picture below). If you are using KDE, you need to use its own networking applet accessible from the KDE Control Center. The rest of the instructions are nearly the same (although the applets will be slightly different).

Network settings
Pic.1 Network settings in GNOME

Now, choose the Ethernet connection (usually identified by the interface eth0) and another dialog should show up. This one is for configurting the specific interface. First make sure that the connection is enabled (a check box). Then, make sure that the Configuration option is set to DHCP. This means that the computer should look for Internet providers in the current network. This setting should be fine for 99% cases. If you require a static IP address bound to your network card, you probably know what you’re doing :)

Ethernet interface properties

Pic.2 Ethernet interface settings

The ethernet interface should be now activated and the computer starts looking for the Internet connection. If it finds one, you’ll probably notice that the networking icon in the GNOME toolbar changes.

Examining connection issues

What is the DHCP connection does not seem to work? Sometimes it happens that the cable modem ceases to grant the computer the Internet connection for the first time. If the modem was connected to another computer or even the same computer but another operating system, it may be that the modem needs to be unplugged first and then connected to the computer again. If may also happen that the network interface needs to be restarted. You can simply deactivate and again activate the connection in the Networking applet. After reactivating, the DHCP client will start looking for connections again. If you don’t like to click a lot, you can do the same in the command line:

  • ifdown eth0 — deactivates the interface eth0 (ethernet card)
  • ifup eth0 — activates the interface eth0
  • dhclient eth0 — manually triggers the DHCP client to lok for connections on eth0

Note that if you are using Ubuntu you need to add sudo before each command (to perform it as root user). If you have another distribution, you need either configure sudo or temporarily become root by entering su - command and perform the commands afterwards.

External articles on cable connection