Ad-hoc networking
An IBSS (Independent Basic Service Set) network, often called an ad-hoc network, is a way to have a group of devices talk to each other wirelessly, without a central controller. It is an example of a peer-to-peer network, in which all devices talk directly to each other, with no inherent relaying.
For example, ad-hoc networking may be used to share an internet connection.
Requirements
- A nl80211 compatible wireless device (e.g. ath9k) on all devices which will connect to the network
Wifi link layer
Since IBSS network is a peer-to-peer network, the steps necessary to set up the wifi link layer should be the same on all devices.
Manual method
See Wireless network configuration#iw for a better explanation of the following commands. Make sure that iw is installed.
Set the operation mode to ibss:
# iw interface set type ibss
Bring the interface up (an additional step like rfkill unblock wifi might be needed):
# ip link set interface up
Now you can create an ad-hoc network. Replace your_ssid with the name of the network and frequency with the frequency in MHz, depending on which channel you want to use. See the Wikipedia page List of WLAN channels for a table showing frequencies of individual channels.
# iw interface ibss join your_ssid frequency
wpa_supplicant
Ensure that is installed, and create a configuration file for it (see wpa_supplicant for details).
Run wpa_supplicant on all devices connected to the network with the following command:
# wpa_supplicant -B -i interface -c /etc/wpa_supplicant-adhoc.conf -D nl80211,wext
Network configuration
The final step is to assign an IP address to all devices in the network. There are multiple ways to do this:
- Assign static IP addresses. See Network configuration#Static IP address for details.
- Running DHCP server on one device. See dhcpd or dnsmasq for details.
- Running avahi-autoipd. See Avahi#Obtaining IPv4LL IP address for details.
If you want to share an internet connection to the ad-hoc network, see Internet sharing.
Tips and tricks
Using NetworkManager
If you use NetworkManager, you can use nm-applet for ad-hoc network configuration instead of the manual method described above. See NetworkManager#Sharing internet connection over Wi-Fi for details.
Custom systemd service (with wpa_supplicant and static IP)
You can use the following templates to enable wireless ad-hoc networking:
/etc/conf.d/network-wireless-adhoc@''interface''
addr=192.168.0.2 mask=24