Creating an Ad-Hoc network

This is a short reference how to create an Ad-hoc network in Linux using the CLI. More detailed article can be found in this Ubuntu guide.

1. Put the wireless interface in ad-hoc mode

iwconfig eth1 mode ad-hoc

2. Set the channel/frequency that you want to use

iwconfig eth1 channel 11

3. Add the name (ssid) for the network you want to create/join. Use single quotes if there is a space in the name.

iwconfig eth1 essid ‘name’

4. Add a WEP encryption key

iwconfig eth1 key ’s:mykey’

5. Bring the interface back up

ifconfig eth1 up

With Atheros based cards you have to take the VAP down in order to create the interface in ad-hoc mode. There are two ways to do this

# rmmod ath_pci

# modprobe ath_pci autocreate=adhoc

# wlanconfig ath0 destroy

# wlanconfig ath create wlandev wifi0 wlanmode adhoc

With cards using ndiswrapper this should work as follows:

# rmmod ndiswrapper

# modprobe ndiswrapper

The example above shows how to setup the network with WEP encryption. If you want to use WPA you have to install wpa_supplicant and configure wpa_supplicant.conf like this:

network={
ssid=”myadhoc”
mode=1
proto=WPA
key_mgmt=WPA-NONE
pairwise=NONE
group=TKIP
psk=”verysecretpass”
}

Then start wpa_supplicant with

# wpa_supplicant -c/etc/wpa_supplicant/wpa_supplicant.conf -ieth1 -Dwext -Bw

Of course you have to put the correct interface and driver name for this to work.