View Full Version : How to share my Cable modem connection with two machines

21-02-2003, 06:52 PM
Surfboard SB4200 Cable Modem
ISP paradise.net.nz
Two machines, one running XP pro & RH8(boot linux from floppy) the other running win98se.
One 5 port hub.

I want to be able to use my Cable modem with both machines independently of the other machine, so I can have either machine on or both and use the modem on either or both.

I have asked paradise for help and have been told that it is possible but that they do not offer any support for it.

At present I have the modem and two machines plugged into the hub(using 3 of the 5 available ports) and have given the machines the same IP addresses but this way I can only use the modem on one machine at a time because of IP conflicts.

Basically I don't won't to have to switch both machines on just to use the modem on whichever machine I'm currently using, plus be able to have both machines use it at the same time if needed.

22-02-2003, 01:24 AM
The only way I know requires one computer to be on at all times, which from your post is not something that you want to do.

So option one is to buy a second NIC and install it on the PC you are going to connect to the modem. This NIC is given your real IP address and the second one connects to your internal network. This means that you will need to set up internet sharing for the second PC to access the internet

The other way is to purchase a cheap PC (you can pick up a low end P1 for less than $100 at Trademe (http://www.trademe.co.nz) ) and run a linux based firewall/router. I personally have used Smoothwall (http://www.smoothwall.org) and found it to be rather good. If you go to Tucows nz mirror (http://inspirenet.linux.tucows.com/index.html) and do a search for Firewall a number of other products are available that might suit you better.

Both of these options require one PC to remain on all the time though.

22-02-2003, 04:14 PM
Yeah thanks mate, I thought it might be the only way to go and have another server ready to go running IPcop.
Didn't really wanna do it that way though so I thought I'd check here first to see if anyone knew of any hacks to do it the other way.
Will have a look at Smoothwall too.
Thanks again.

22-02-2003, 04:22 PM
The flyier for the SB4200 indicates it supports 32 users - is there not some mention of NAT in your user manual?

Susan B
22-02-2003, 04:48 PM
> Both of these options require one PC to remain on all the time though.

Funny this should crop up when I was just thinking about that today. Gorela, do you mean that the SmoothWall computer needs to be on all the time literally, or just when internet connection is required? Thus, one would turn the SmoothWall computer on then one or both computers that wish to go online?

22-02-2003, 05:04 PM
Apparently there is no NAT in the SB4200 - the multiple user facility has to be provided by the ISP.

The only 'non PC' solution, then, would appear to be to add an external NAT router - not a cheap solution.

Steve Askew
22-02-2003, 06:20 PM
The guy that installed my SB4200 cable modem said he could provide a USB internet connection sharing hub for about $400 installed (I think by memory) & each computer could run independently.
If you are in Wellington area & want more info I'm sure I have his number somewhere here.

Cheers Steve

22-02-2003, 11:39 PM
Howdy Susan, :)

There is no problem turning the Smoothwall PC on when you need it. It would purely depend on how you have it set up. :)

I have it turned on all the time (as I run it without a monitor/keyboard/mouse) so it is awkward to reconnect everything. I use it as a DHCP server for portions of the network and certain computers aren't handy to it if they require internet access. Also, if you are using it as a proxy server turning it off and on kinda defeats the purpose.

If you have surplus keyboards and mice or the computer boots successfully without then there would be no concerns.