The situation

In May 2003 I moved into a new house in Edinburgh where we were able to get a cable broadband connection from Telewest Broadband.

Please note that I no longer use Telewest Blueyonder as my ISP as I've moved from Edinburgh to Anstruther where there is no cable access; I now use BT Broadband. However, I've kept this guide online as many people have told me how useful they have found it.

While we were living in Inverness with a standard 56K modem connection we managed to network our two PCs together and use a Proxy Server to allow the second PC to connect to the internet, thus:

But now we had a broadband connection how could we also connect BOTH computers to the broadband internet connection?

I did some searching and reading around and discovered that what I needed was a cable router with a built-in switch, like this:

This set-up would also allow my old PC running Windows for Workgroups 3.11 to also connect to the network.

{^top}

Router? Switch? What?!

If these terms are already confusing you a little, I recommend that you read my basic introduction to networking page.

In short, a router allows two separate networks to communicate with one another (in this case the LAN and the internet), and a switch allows the computers to communicate with one another in a well-managed way.

{^top}

Cable Modem

The cable modem that Telewest supplied us with is a Scientific-Atlanta WebSTAR DPX100.

This modem takes a co-axial input (like that into your TV) and can be connected to your PC via USB or a CAT5 network patch cable (straight).

I connect my modem to my router/switch via a CAT5 network patch cable, but I don't suppose it matters which method you use so long as you can connect your modem to your chosen router.

{^top}

MAC Address

THIS SECTION IS NOW REDUNDANT -- YOU NO LONGER NEED TO REGISTER THE MAC ADDRESS.

As a security measure with Telewest's cable broadband connection you must register the MAC Address of the Network Interface Cards (NICs) that you wish to be able to use with your cable modem.

According to Webopedia: MAC is "[s]hort for Media Access Control address, a hardware address that uniquely identifies each node of a network". A MAC Address is in the format of six hexadecimal numbers, e.g.

Only MAC Addresses recognised as being registered with Telewest will be able to connect to the internet via your cable modem.

When the Telewest Broadband engineer installed the broadband connection he informed Telewest Broadband of the MAC Address of my network card. He informed me that I can register up to five (5) MAC Addresses on the Blueyonder Self-Care website: http://selfcare.blueyonder.co.uk/

{^top}

Register MAC Addresses

THIS SECTION IS NOW REDUNDANT -- YOU NO LONGER NEED TO REGISTER THE MAC ADDRESS.

I recommend that you register your main PCs' MAC Addresses plus the MAC Address of your Router. This is just in case something happens to your router or any of your PCs, you will still be able to connect to the internet one way or another. (Of course, if your cable modem goes belly-up then you're stuffed!)

{^top}

How to find your MAC Address

WHILE YOU NOW NO LONGER NEED TO REGISTER THE MAC ADDRESS IT CAN BE USEFUL TO KNOW YOUR MAC ADDRESS.

If you have installed a new network card the documentation that came with it should tell you; similarly the MAC Address of your Router should have come with the product, and is sometimes even printed on a label on the rear or bottom of the unit.

If you still cannot find where the MAC Address was printed, or the unit is second hand, fear not. You can still find out the MAC Address.

NIC MAC Address from Windows

If you have TCP/IP installed (and you should, otherwise how are you reading this?!) then pull up a DOS Prompt window and type the following:

then hit the Enter key.

Windows for Workgroups 3.11 screenshot

Windows XP Professional screenshot

You may also find that the DHCP Table on your router may inform you about the MAC Addresses of the NICs connected. This screenshot (below) is taken from a Netgear RP114, in the Maintainance section:

{^top}

Cable Modem MAC Address

In a web-browser, calling up the IP address of my cable modem (Scientific-Atlanta WebSTAR DPX100) I am able to see the system and status information of the modem, including the MAC Address of the modem itself.

{^top}

Router MAC Address

I am able to find out the MAC Address of my Netgear RP114 router from the Status page of my Cable Modem; this page shows all information about customer premise equipment (CPE) connections.

{^top}

Choosing a Router/Switch

I chose a Netgear RP114 Router/Switch with built-in Network Address Translation (NAT).

NAT is the bit that does the cunning work of keeping the LAN hidden behind the router. All internet requests are passed to the NAT, which keeps a table of who has asked for what. When any information comes in from the internet the NAT looks up its table to see if any of the PCs behind the router have requested this information. If they have they pass it on, if not they drop it.

This keeps your network a little more secure, but not as secure as if it also had a dedicated hardware firewall.

The Netgear RP114 has one port for a WAN connection (in this case it plugs into the WebSTAR Cable Modem) and four ports for LAN connections.

As far as I am aware, Netgear do not manufacture the RP114 any more, but they do have a good range of new routers.

In the example below I am going to walk through how to set up an RP114 with a Blueyonder broadband account; your router and setup may be similar.

{^top}

Before you start

I received these thoughts from Chris Rick, which I thought useful enough to add here:

Your blueyonder router connection note was absolutely brilliant. I have overcome a long standing problem because your note enabled me to set up a second router and then go on to re-set my original router.

Thank you so much!

I have one thing that you could add that most people are unlikely to bump up against. Nothing worked when I went through your note first time round after switching routers. I sat on the floor and cried after over an hour of experiments.

All was solved when I did what they call a 'root boot':

1. Turn off the router.
2. Turn off the modem.
3. Unplug it from mains.
4. Wait a minute.
5. Plug in modem.
6. Turn it on.
7. Wait until it settles down with the lights.
8. Turn router on.

Then follow your note.

Thanks for the input Chris.

Setting up the Router/Switch