[ILUG-BOM] networking query -- wifi

Dinesh Joshi dinesh.a.joshi@[EMAIL-PROTECTED]
Mon Jul 16 00:37:15 IST 2007

On Sun, 2007-07-15 at 16:34 +0530, Dr. Sharukh K. R. Pavri. wrote:
> Ok, 
> As I wrote some time ago, I am trying to connect two pcs via wifi. 
> I can see the other card via iwlist device scan. But I can't ping each
> other, this is what I get.
> ---------------------------------------------------
> sharukh at natrum:~$ ping -c5
> PING ( 56(84) bytes of data.
> From icmp_seq=2 Destination Host Unreachable
> From icmp_seq=3 Destination Host Unreachable
> From icmp_seq=4 Destination Host Unreachable
> From icmp_seq=5 Destination Host Unreachable
> --- ping statistics ---
> 5 packets transmitted, 0 received, +4 errors, 100% packet loss, time
> 3998ms
> , pipe 3
> -----------------------------------------------------
> So what do I need to do ? What more info should I send ?

Ok, wifi needs to be setup this way:

1. Setup the wireless parameters
2. Configure the IP settings

For the two PCs to first establish communication they should have the
same ESSID, channel and mode.

ESSID is like the name of the network. For example: HOMENET ( use all
uppercase / lowercase ).

Channel should be set to 13 or 11 or whatever you like but this setting
should be the same on both PCs.

Finally, the mode should be ad-hoc. This mode enables P2P connection
between wireless device.

After you ensure that these parameters are the same you issue iwconfig
( ? ) to see if the two machines have "bound". I'm not sure if this
happens in the adhoc mode but you should see a valid hex number for
Access Point: 00:06:25:9A:50:C8 or Cell parameter in the output. This
means that both PCs actually "see" each other.

The next step is pretty simple. You just ensure that you assign the
wireless interface the right parameters. Both machines should have the
same IP range and belong to the same class of networks. Eg.

You should be able to ping the machines. Also disable firewalls on both
machines incase you have it running. Remember, dmesg is your friend to
troubleshoot problems.

Linux drivers have a nifty debug switch. Incase you're not able to
understand whats wrong, just remove the kernel module using rmmod and
then modprobe it in the debug mode. It should be something like modprobe
ipw2200 debug=1. Not 100% sure though.

Dinesh A. Joshi

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