Share Internet Connection Problem

[fire_dragon]

Dear friends,
I am new to Linux and I was trying to do the following thing.

I had to move my computer away from my router and I cannot/don't want to put a cable to it again because I would have to drill through walls and such stuff.

Solution: order a wlan stick, which arrived yesterday and also working well now.

In the meantime, I thought about the following:

Connect through a network cross over cable from my PC to my wifes laptop, establish a working network connection and share the laptops internet connection, which is connected over wlan to my router, with my PC.

The laptop runs Windows 7, the PC Kubuntu 12.04.

I managed to set up the network connection, I am able to transfer files from PC to laptop. I'm also able to transfer files from laptop to PC. I set up the laptop (in windows 7) to allow the PC to use its internet connection. This works when I use PC windows 7 to laptop windows 7, so I guess the windows 7 side is set up properly. I guess the problem is now the pc with kubuntu.

Then I read somewhere that I have to enable internet sharing on the linux pc also, which doesn't makes much sense to me, but anyway I tried this, and I somehow cannot enable it. It seems I have to have a second ethernet device running. Which makes sense again, because how can I share a computers internet connection, when there is actually no connection availible. Now I am able to share internet connection once I establish an internet connection with the wlan stick on kubuntu. Before I did this, I couldn't manage to enable internet connection sharing.

OK, now I would like to:

establish an internet connection through the windows 7 laptop over the cross over cable without using the kubuntus wlan stick.

I tried for 3 days to do this until the wlan stick arrives and now i want to know how to do it without the "workaround" with the wlan stick.

thank you.

[SteveRiley]

Undo everything you did to Kubuntu. Just let it use ordinary DHCP and connect it to the south side network port on the laptop (that is, the non-Internet connection). ICS on your wife's laptop will offer a DHCP lease to Kubuntu, which Kubuntu will use normally.

[fire_dragon]

I deleted every wired connection and added a fresh wired connection which uses "automatic DHCP". I also did not specify the ip and subnet on the windows pc this time. As a result I am not even able to connect to the notebook anymore, the folder sharing is becoming only available when I specify the ip and subnet. And even then the network "workgroup" is becoming visible only after quite some while and not immediately. I am not sure if this is also a normal behaviour. I might made a mistake or I did miss something when setting up the network. I connect with driver r8169 over eth0 via cross cable to the notebook.

[SteveRiley]

Let's check my interpretation of your desired situation first. In the description below, imagine that "north" means pointing to the Internet, and "south" means away from the Internet and towards a device or a local network. (This is typical net-geek lexicon, BTW.)

* You have a router whose north interface is connected to the Internet.
* Your wife's computer, running Windows 7, has two network interfaces.
* The north interface is connected to the router.
* The south interface you wish to make available for sharing.
* Your computer, running Kubuntu, has a single network interface.
* You want to connect this to the south interface of your wife's computer, so that you can access the Internet via her her computer.

Is this correct? Please fill any gaps in my understanding. I am familiar with the Windows Internet connection sharing feature, but I need a complete understanding of your setup before I can offer advice.

[fire_dragon]

You're 100% correct.

Router connects to internet. (north)
Win7 notebook connects to router via wireless lan (north)
Win7 notebook connects to kubuntu pc via cross over lan cable (south)
kubuntu pc connects to win7 notebook via cross over lan cable (north)

[Qqmike]

Have something similar here (if I understand you all correctly):
I have 2 PC's. A modem/router is connected to the Internet (DSL in my case). A 5-port Linksys switch is then connected to that router (to the "south" port off the router). Then each PC is connected to a south-pointing port of the switch (there are 5 such ports on that switch, and so now two are being used by the 2 PC's). (This solution does require the swicth, which in 2009 was just $30.)

[SteveRiley]

Microsoft publishes an article on ICS, which will help you get your computers set up properly for this.

Typically, though, ICS is used only when there's no other router on the network -- the ICS computer becomes a router. Since you already have a router, your planned configuration is suboptimal for the Kubuntu computer: all its traffic will pass through two routers. Your original idea of using the wireless interface on your Kubuntu computer is a better one.

[fire_dragon]

Well, since I can successfully use the internet connection sharing when I boot Win7 on the PC --> Win7 Notebook --> Router, but not Kubuntu on the PC --> Win7 Notebook --> Router, I don't know what to do. The Kubuntu Pc had no possibility to access the router directly.

I am using my W-LAN stick now and guessable have to forget about this idea which is now actually obsolete, but still bugging me because I spent 3 days of unsuccessfully trying to set something up, which should be possible.

Thanks for your help.

[SteveRiley]

Please show the output of

cat /etc/network/interfaces

Also, are/were you simply wanting to use the dual-homed Windows PC as a router to get to the Internet, or did you want to perform file and folder sharing between the two computers?

[fire_dragon]

xxx@kubuntu:~$ cat /etc/network/interfaces
auto lo
iface lo inet loopback

xxx@kubuntu:~$

Actually the file/folder sharing between the Kubuntu PC and Win7 Laptop worked. I had to install Samba for this on the Kubuntu PC. But file/folder sharing was not my goal, but it proved to me that the network setup itself was working.

The Win7 Laptop is not dual OS, only Win7, but the Kubuntu PC has multiple OS, which two are Win7 and Kubuntu. Everything works if I use Win7 on both.

[SteveRiley]

The contents of your /etc/network/interfaces is correct.

I described your wife's computer as dual-homed, not dual-boot. Dual-homed refers to a computer with two active network interfaces. A Windows 7 computer configured with ICS automatically assigns the IP address 192.168.137.1 to the south interface and advertises DHCP to any computer connected to that interface. So your Kubuntu computer should have received an address in the subnet 192.168.137/24, along with DNS server and default gateway of 192.168.137.1.

However, in spot-checking various items in a Google search, I'm seeing some reports that non-Windows clients have trouble working with ICS's automatic address assignment. It isn't real DHCP, so I guess it isn't all that surprising. (I will refrain myself from ranting about yet another half-assed "feature" I've discovered in Windows subsequent to my departure from Microsoft. Sheesh, the suckage really appears to be ceaseless.)

If you still want to experiment, you can try to manually configure the network interface in your Kubuntu PC. Make it look like this:

[fire_dragon]

Sadly it did not work.

I tried it with another distribution (openSUSE) also with KDE and I got the internet sharing working quite quickly.

Maybe something was just wrong with my Kubuntu installation or configuration.

Thank you for your help.