Home networking for 3 computers (Windows and Linux) [closed]

Question

I want internet connection and folder sharing among 3 computers. One is always on and directly connected to internet (Win XP Pro). Currently it shares Internet connection with just another Windows PC with ICS (it has 2 NICs). I want to extend internet and folder sharing to the 3rd PC which might run Linux from time to time.

What do I have to buy (a switch?) and what IP configuration should I use? (as I'm not using DHCP). I also need help with the Linux networking configuration (I'm using Linux Mint 6 KDE CE).

Answer 1

I don't like connecting Windows PCs directly to the internet. I would buy a standard consumer internet router (like this, $30 at NewEgg), connect it to the internet, and connect the computers to it. It will do the DHCP if you like, and the configuration is pretty clear. It will protect your systems from the craziness on the internet. Then you can turn on file/folder sharing on the computers without risk, and the Windows/Linux network configuration becomes straight-forward; follow the wizards.

If you want to roll your own, I would take the PC with 2 NICs and install the free Astaro Security Gateway software on it. It is a Linux "appliance" that is a full-featured firewall. I use several of their commercial products at work and am pleased.

I realize that this doesn't specifically answer your question, but I think it gets you where you want to go in a better fashion.

EDIT: You noted the CDMA terminal. If the PC connects to it using TCP/IP over an Ethernet NIC, the Astaro should work fine. If you are going to keep the Windows PC as the "firewall", I suggest that you put a bunch of web research into securing that PC. Start here.

ALSO: You can use the Gibson Research Corp Shields Up website to test external access to you PCs. It works very well.

Answer 2

The easiest and most common way to do this is to buy a router that is permanently connected to the internet and uses DHCP to dish out IP address's to the network. If you need static IP's on machines most routers will allow you to set reservations.

If you were to use this method the linux machine would most likely work out of the box, most distros use DHCP by default.

Alternatively if you don't want to use a router, you will need a hub or switch for all the clients to connect to and provide all machines with a static IP in the same range, along with a gateway IP for the machine that is providing the shared internet access.

Answer 3

A switch should indeed be sufficient; if you plan on continuing to use a computer as a gateway connected to the internet, if not you'll need a router instead.

If you're not using DHCP you'll need to ensure all your computers are on the same subnet (normally 192.168.x.x) and netmask. I'd suggest you use 192.168.0.1, 192.168.0.2 and 192.168.0.3 for your computers and the netmask 255.255.255.0.

You can set a static IP address in /etc/network/interfaces on Linux similar to this:

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
  address 192.168.0.3
  netmask 255.255.255.0
  gateway 192.168.0.1

Answer 4

Do you run any servers on your WinXP machine? On the assumption that you are not, then by far the safest way to do things is to buy any reasonable network switch that supports DHCP and let that be your interface to the network for all machines. Then you don't need to configure internet connection sharing on the WinXP machine.

Note that I believe when you configure internet connection sharing, that WinXP automatically provides DHCP services to the machines connected to the 2nd network. Almost all Linux installs today will either default to DHCP or are trivially configurable as DHCP clients. Thus, adding the Linux machine to the network will be trivial. Ensure that the NIC is configured as DHCP and then plug it in.

I use my Linux server as my direct connection to the internet, but that's because I run several servers on my Linux server (I'm paying for a network connection that allows me to run any services I want, and I have a static IP address) and also so that I can run a packet filtering firewall on my Linux server to protect the rest of my network from external attack. In your case, an external network switch that provides DHCP would provide this protection for you -- the switch would be exposed to attack and nothing else. Only if they could hack the switch would they be able to hack into your network. (Of course, I'm ignoring viruses and trojans and spywhere here, most of which are installed by insecure web actions, via Email, or by otherwise tricking people into installing them.)

If you don't want to do this and you want the most minimal change to your current network, then as I said, I believe that ICS sets up a DHCP server. Just install Linux on the new machine, configure its NIC for DHCP, and plug it into that 2nd network. It should just work. I helped my parents set up a network much like this, and have connected my Linux laptop to their network with no difficulty.

EDIT: Yes, an article at Microsoft.com, Internet Connection Sharing with Windows XP, confirms that ICS does automatically configure a DHCP server on the host machine.