Creating a wireless ad-hoc network

APwrs · #1 10-09-2006, 03:19 AM

I would like to create a very small wireless ad-hoc home network. I've asked this question on a different forum and never really got any help, and I've spent the past few days searching for this both in forums and on the Internet in general to no avail. My ultimate goal is something grander than this, but this is where I want to start, and I'm hoping to receive some help here.

Right now, I'm just trying to network two computers. My desktop and my laptop. Both are running Ubuntu 6.06. Both have wireless network adapters which are properly supported.

On my desktop, I enable the wireless network adapter and give it the following configuration:

ESSID: SUPERTEST
IP: 192.168.0.1
Netmask: 255.255.255.0
Gateway: <empty>

Then I issue the following command:

sudo iwconfig wlan0 mode ad-hoc

Then just for good measure I restart the network. Next I go to my laptop and enable its wireless network adapter and a quick check of:

iwlist eth1 scan

shows that it can see the broadcast from my desktop. So then I configure my laptop like this:

ESSID: SUPERTEST
IP: 192.168.0.2
Netmask: 255.255.255.0
Gateway: I've tried using both 192.168.0.1 here and leaving this empty

Then I also set it to ad-hoc mode and restart the network.

After I've got everything set up like that, my laptop (192.168.0.2) can't ping my desktop (192.168.0.1) or vice-versa. Firewalls aren't an issue here. Am I missing something? Any help would be greatly appreciated.

**Icarus** · #2 10-09-2006, 09:06 AM

I believe that AdHoc requires you to set the Channel to connect, give that a try

sudo iwconfig wlan0 mode ad-hoc essid supertest channel 6

or something like that...
Digging around on the Ubuntu forms it looks like you could use kwifimanager to setup an AdHoc. Here's the thread that talks about it in case you didn't find it

APwrs · #3 10-09-2006, 12:08 PM

Both the desktop and laptop are sent to channel 10. I've also tried other channels to make sure it wasn't a frequency issue. I'm sure I'm not the first person to want to do this, but it seems good information on this is rather scarce.

I'll take a look at the thread you suggested and I thank you for it, but I don't think the problem is actually getting the wireless network adapters into ad-hoc mode, as I seem to be able to do that okay, and they're listed as being in ad-hoc mode when checked with iwconfig.

APwrs · #4 10-09-2006, 04:19 PM

This is very confusing. I read the thread and set up my two systems the exact same way (except with different IP addresses of course) and it didn't work for me. I changed some settings around and it still didn't work for me. It looks like it should work because both the desktop and the laptop have the same cell and are on the same channel, but whenever I try to ping I get this:

myuser@myplace:~$ ping 192.168.0.3
PING 192.168.0.3 (192.168.0.3) 56(84) bytes of data.
From 192.168.0.2 icmp_seq=2 Destination Host Unreachable
From 192.168.0.2 icmp_seq=3 Destination Host Unreachable
From 192.168.0.2 icmp_seq=4 Destination Host Unreachable

APwrs · #5 10-09-2006, 07:16 PM

I find it interesting that this thread was moved to mobile computing. The situation would be exactly the same if I was trying to build a wireless ad-hoc network between two desktop computers. It just so happens that in this case, one of the computers is a laptop. The fact that it's a laptop isn't the issue here. The network is the issue here. Hence why I originally posted this in Networking.

**Icarus** · #6 10-10-2006, 01:04 AM

Quote:

Originally Posted by APwrs

I find it interesting that this thread was moved to mobile computing. The situation would be exactly the same if I was trying to build a wireless ad-hoc network between two desktop computers. It just so happens that in this case, one of the computers is a laptop. The fact that it's a laptop isn't the issue here. The network is the issue here. Hence why I originally posted this in Networking.

Laptop's, PDA's and Wireless related questions.
This is more of a wireless question then a netowrk one...unless you have a habit of setting your Desktop's non-wireless NIC up as an AdHoc

APwrs · #7 10-10-2006, 03:40 AM

I think I may have found what has been causing the problem. It turns out that I've been setting my network up properly all along, but Ubuntu seems to have some issues with the wireless network adapter I'm using on my desktop.

I wasn't getting anywhere when I was trying to figure this out, so I decided to download the live CDs of Mandriva 2007 and the Edgy Eft beta. I booted up the Mandriva CD and configured my ad-hoc network and the desktop and laptop were able to ping each other. Then I booted up the Edgy beta CD and configured my ad-hoc network the same way and saw the same results that I've been seeing all along while trying to figure this thing out. It also worked fine when I tried doing this with Windows on my desktop.

So it would seem that Ubuntu just doesn't like the wireless network adapter I use on my desktop. It works fine in managed mode and can connect to an access point, but it just doesn't want to work properly in ad-hoc mode.

The only difference I could see is that in Ubuntu my network adapter is listed as being IEEE 802.11-DS, whereas in Mandriva my network adapter is listed as being IEEE 802.11b, so that makes me think it might be a driver issue.

con · #8 10-10-2006, 03:48 AM

I think it has to do with drivers.... I have a laptop with built-in wireless (ndiswrapper) and a desktop for which I bought a pci wlan nic (native driver). Wanted to do what you are trying to do, but problem was the laptop couldnt create a new ad-hoc network, only connect to an existing one and that wasnt without its clutches.... The desktop on the other hand didnt have any problems. Are using ndiwrapper on both machines? If so I dont think it will work...

PS. Hope you arent gonna share internet between the two machines...ad-hoc has no security what-so-ever i.e no WEP or WAP, and it doesnt require any authentication at all. Get an Access point instead.

APwrs · #9 10-10-2006, 07:48 PM

The laptop is using the ipw2100 driver provided by the kernel, and my desktop is using the Atmel driver provided by the kernel. Neither is using ndiswrapper.

Also, WEP does work with ad-hoc. I've done extensive testing to make sure. The key can be configured either through the distro's networking tools or through the iwconfig command, and once the key is configured, if two ad-hoc nodes don't share the same key, they can't ping each other or communicate with each other in any way at all. It just has to be configured in the proper way.

I solved my problem with virtualization. I created a virtual machine using VMware and installed Mandriva 2007 into it, then gave it access to the wireless networking adapter, so it basically acts like a virtual router, and I can bring it up and turn it off whenever I need to.