アドホックネットワークのソースを表示

[[Category:無線ネットワーク]]
[[en:Ad-hoc networking]]
[[zh-CN:Ad-hoc networking]]
{{Related articles start}}
{{Related|ネットワーク設定}}
{{Related|ワイヤレス設定}}
{{Related|ソフトウェアアクセスポイント}}
{{Related|インターネット共有}}
{{Related articles end}}
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 [[Internet sharing|share an internet connection]].

== 要件 ==

* A nl80211 compatible wireless device (e.g. ath9k) on all devices which will connect to the network

== Wifi リンク層 ==

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.

{{Tip|It is possible to create complex network topologies, see [http://wireless.kernel.org/en/users/Documentation/iw/vif Linux Wireless documentation] for advanced examples.}}

=== 手動設定 ===

{{Warning|This method creates '''unencrypted''' ad-hoc network. See [[#WPA supplicant]] for method using WPA encryption.}}

以下で使っているコマンドの詳しい説明は[[ワイヤレス設定#手動セットアップ]]を見て下さい。また、{{Pkg|iw}} を[[pacman|インストール]]しておいてください。

動作モードを ibss に設定:

 # iw ''interface'' set type ibss

インターフェイスを立ち上げる ({{ic|rfkill unblock wifi}} などの設定が必要に鳴る場合もあります):

 # 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 [[Wikipedia:List_of_WLAN_channels#Interference_Concerns|List of WLAN channels]] for a table showing frequencies of individual channels.

 # iw ''interface'' ibss join ''your_ssid'' ''frequency''

=== WPA supplicant ===

{{Note|This method creates ad-hoc network using WPA encryption. WPA2 is currently not supported (August 2013).}}

Ensure that {{Pkg|wpa_supplicant}} is [[pacman|installed]], and create a configuration file for it (see [[WPA supplicant]] for details).

{{hc|/etc/wpa_supplicant-adhoc.conf|<nowiki>
ctrl_interface=DIR=/run/wpa_supplicant GROUP=wheel

# use 'ap_scan=2' on all devices connected to the network
ap_scan=2

network={
    ssid="MySSID"
    mode=1
    frequency=2432
    proto=WPA
    key_mgmt=WPA-NONE
    pairwise=NONE
    group=TKIP
    psk="secret passphrase"
}
</nowiki>}}

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

== ネットワーク設定 ==

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 ==

=== NetworkManager を使う ===

If you use [[NetworkManager]], you can use ''nm-applet'' for ad-hoc network configuration instead of the manual method described above. See [[NetworkManager#Ad-hoc]] for details.

{{Note|NetworkManager does not support WPA encryption in ad-hoc mode.}}

=== カスタム systemd サービス (wpa_supplicant と固定 IP) ===

You can use the following templates to enable wireless ad-hoc networking:

{{hc|/etc/conf.d/network-wireless-adhoc@<interface>|<nowiki>
addr=192.168.0.2
mask=24
</nowiki>}}

{{hc|/etc/systemd/system/network-wireless-adhoc@.service|<nowiki>
[Unit]
Description=Ad-hoc wireless network connectivity (%i)
Wants=network.target
Before=network.target
BindsTo=sys-subsystem-net-devices-%i.device
After=sys-subsystem-net-devices-%i.device

[Service]
Type=oneshot
RemainAfterExit=yes
EnvironmentFile=/etc/conf.d/network-wireless-adhoc@%i

# perhaps rfkill is not needed for you
ExecStart=/usr/bin/rfkill unblock wifi
ExecStart=/usr/bin/ip link set %i up
ExecStart=/usr/bin/wpa_supplicant -B -i %i -D nl80211,wext -c /etc/wpa_supplicant-adhoc.conf
ExecStart=/usr/bin/ip addr add ${addr}/${mask} dev %i

ExecStop=/usr/bin/ip addr flush dev %i
ExecStop=/usr/bin/ip link set %i down

[Install]
WantedBy=multi-user.target
</nowiki>}}

== 参照 ==

* [https://help.ubuntu.com/community/WifiDocs/Adhoc Ubuntu community wiki WifiDocs/Adhoc]
* [http://www.ubuntugeek.com/creating-an-adhoc-host-with-ubuntu.html Manual about creating an Ad-Hoc network on UbuntuGeek]
* [http://go2linux.garron.me/linux/2011/03/share-your-3g-internet-connection-over-wifi-linux-ipod-touch-925 Share your 3G Internet connection over wifi]