Cable Modem Guide by Joey
Created on August 13th, 1999.
Last updated on September 28th, 2002.

This guide was written back in 1999 when most Linux Distributions didn't configure everything for you during the installation. If for some reason your Cable Modem was not properly configured during the installation, the guide below might come in handy for you. It requires that you have Linuxconf installed on your machine. You might find additional configuration tools on your machine such as DrakConf if you run Mandrake. These can also be used to configure your internet connection.

Without further delay, here is the original guide.

So that linux-ignorant technician just left your house and of course they didn't install & configure your new cable modem in Linux. This is where this guide comes into play.

After you physically install the Ethernet card into your machine, boot into Linux and recompile the kernel with support for the ethernet card. See the Cable-Modem-HOWTO for information on what type of Ethernet card comes with each different cable modem ISP. Once that is done and you rebooted with the new kernel, you should see something like this when Linux starts to load: 

ne2k-pci.c: PCI NE2000 clone 'Winbond 89C940' at I/O 0xd800, IRQ 10.

eth0: Winbond 89C940 found at 0xd800, IRQ 10, 00:20:78:16:2B:E8.

If you see something similar to the above, great, it means your card has been detected, if not, check the kernel again to see if you compiled in the right drivers.

Now after everything goes okay, get out that paper they gave you containing all the information you will need, such as your IP address, gateway, nameservers etc. Log into your system as root, (in X or console) and type:

linuxconf

Go into the Networking / Client tasks section.

Step one, Basic Host Information



The follow things need to be edited.

> Host name: Enter the hostname they gave you, such as c762529-a.rsflok1.ar.home.com

IP Address: Set that to the IP they gave you, such as 24.116.9.12.

Netmask: Set it to 255.255.255.0

Net Device: Set this to eth0 unless you have more then one ethernet card in your machine. If you have 2 and this one will be the second card, set it as eth1

Accept the changes and now go into the Name server specification (DNS) section.

Step two, Name server specification (DNS)



default domain: Set that as the subdomain info supplied on the paper they gave you. It should resemble something like rsflok1.ar.home.com

nameserver 1: Set this as the primary DNS IP they gave you, such as 24.2.9.37

nameserver 2: Set this as the secondary DNS IP they gave you, such as 24.2.9.38

Accept the changes and now go into the Routing and gateways section.

Step three, Routing and gateways



Go into the Defaults section under the Routing and gateways section and edit the following:

Default gateway: Set this as the gateway they gave you on that paper. An example is 24.116.12.1

Accept the changes and go into the other routes to networks section and edit the following:

Add a new route by hitting the "Add" button. Set the gateway as the IP address they gave your modem. Again, see the paper they gave you. Set the destination as the same IP you used in the above section for the gateway, in this case it would be 24.116.12.1. The Netmask is optional but if you must put it in, use 255.255.0.0

Step four, Final Configurations



Save everything in linuxconf and exit it. Now reboot your system and watch carefully for something that looks like this:

Starting up eth0      [OK]

If that worked then great, if not, check your settings once more.

Now log in as root and type dhcpcd -h your_hostname. An example would be:

dhcpcd -h c762529-a

Now if everything worked you should see something like this:

dhcpcd: your IP address = 24.116.16.169

Congrats, you are now online with your cable modem, go download the kernel in less then a minute and make sure to tell all your friends on dial-up about it. =)

Now this is a very rough guide, and it might (probably) not work for everyone. These are the steps I took to get mine working, and mine works fine. Some of the problems you might run into are problems getting your NIC detected, which I know about since I had a big problem with my 3com 509b. To get a 3com 509b NIC to work, leave Plug and Play enabled and compile the kernel driver as a module. Then as root type pnpdump >>/etc/isapnp.conf and edit the /etc/isapnp.conf file. Look for a line that looks like this:

#(INT 0 (IRQ 3 (MODE +E)))

Now uncomment it (remove the # infront of the line) and then uncomment the line that looks like this:

#(ACT Y) Now type isapnp /etc/isapnp.conf and if you don't get an error it means it detected your card and it is properly configured. Now just reboot and you should see that Starting up eth0 stuff again. If the isapnp command didn't work, try changing the IRQ address to a higher number and redoing the process again.


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