|Version||Status||Date Updated||Updated By|
|810||relevant||20th Sept 2010||phenigma|
This tutorial describes how to add Access Point functionality to your LinuxMCE Core/Hybrid. The Core/Hybrid will then act as a WiFi access point permitting wireless devices to connect to the core, the internal network and the Internet. The drivers you choose will depend on your specific hardware. Setting up an Access Point on your core allows you to use wireless orbiters such as the WebDT 366 or Nokia N800/N900 without installing a separate wireless access point on your network.
Using nl80211 drivers (from back-ports)
A lot of modern hardware works. Look up your device at http://wireless.kernel.org/en/users/Devices to determine which driver your card uses. The driver needs to support AP, you can check that the driver has this support at http://wireless.kernel.org/en/users/Drivers/. If the driver does not have AP support then you will not be able to operate the card as an Access Point.
Two Wireless-N adaptors that are known to work:
- Atheros Communications Inc. AR928X Wireless Network Adaptor (PCI-Express) (rev 01)
- This was pre-installed on a Zotac IONITX-A-U Atom N330 1.6 Ghz
- Uses the ath9k driver
- Atheros AR9280 MAC/BB Rev:2 AR5133 RF Rev:d0
- This is a D-Link DWA-522 Extreme N PCI Adaptor
- Uses the ath9k driver
- LinuxMCE 0810 BETA - Snapshot DVD 25289
- -> eth0 connects to internal network LMCE
- -> eth1 connects to the internet
- -> wlan0 is the wireless card
Add the intrepid-backports repository
Adding the intrepid-backports repo gives us access to newer wireless drivers.
$ echo 'deb http://archive.ubuntu.com/ubuntu intrepid-backports main universe' | sudo tee -a /etc/apt/sources.list $ sudo apt-get update
Install required packages
Install compat-wireless drivers including the mac80211/cfg80211 modules and the network bridge utilities.
$ sudo apt-get install linux-backports-modules-intrepid bridge-utils
Download, build and install hostapd
The hostapd package that ships with intrepid (0.5.10) is outdated, newer functionality is required. Grab the most recent version that works with the compat-wireless drivers that we installed. 0.6.10 is the newest in the 0.6.x tree but it has a bug that causes it to fail with some cards, use 0.6.9.
Install build dependencies for hostapd
$ sudo apt-get install libnl-dev libssl-dev
Get hostapd 0.6.9
$ wget http://w1.fi/releases/hostapd-0.6.9.tar.gz $ tar xvf hostapd-0.6.9.tar.gz $ cd hostapd-0.6.9/hostapd $ cp defconfig ./.config
Edit the .config file to enable the proper drivers:
- Enable nl80211 driver
- Enable IEEE 802.11n (High Throughput) support
Build and Install hostapd
$ make $ sudo make install
Copy the config file to /etc/hostapd
$ sudo mkdir -p /etc/hostapd $ sudo cp hostapd.conf /etc/hostapd
Make a backup of your original interfaces file:
$ sudo mv /etc/network/interfaces /etc/network/interfaces.bak
The interfaces file shown here is based on the setup described in the overview above.
auto lo eth1 br0 eth0 # Loopback Interface iface lo inet loopback # Internet Interface iface eth1 inet dhcp # LAN Interface iface eth0 inet manual up /sbin/ifconfig eth0 up down /sbin/ifconfig eth0 down # Wireless Interface iface wlan0 inet manual # Wireless/LAN Bridge iface br0 inet static address 192.168.80.1 network 192.168.80.0 netmask 255.255.255.0 broadcast 192.168.80.255 pre-up /usr/sbin/brctl addbr br0 pre-up /usr/sbin/brctl addif br0 eth0 pre-up /usr/local/bin/hostapd -B /etc/hostapd/hostapd.conf pre-up /usr/sbin/brctl addif br0 wlan0 up /sbin/ifconfig br0 inet 192.168.80.1 broadcast 192.168.80.255 netmask 255.255.255.0 post-down /usr/sbin/brctl delif br0 eth0 post-down /usr/sbin/brctl delif br0 wlan0 post-down /usr/sbin/brctl delbr br0
Edit /etc/hostapd/hostapd.conf and verify/change the following:
interface=wlan0 driver=nl80211 ssid=yourssidhere hw_mode=g ieee80211n=1
Configure the dhcp server to respond to request from devices on the bridge instead of the wired connection alone.
$ echo 'INTERFACES="br0"' | sudo tee /etc/default/dhcp3-server
All security/encryption related settings are in /etc/hostapd/hostapd.conf. Edit this file as needed. A good starting point for a wpa & wpa2 enabled access point is:
macaddr_acl=0 auth_algs=1 ignore_broadcast_ssid=0 wpa=3 wpa_passphrase=YourPassPhrase wpa_key_mgmt=WPA-PSK wpa_pairwise=TKIP rsn_pairwise=CCMP
Restart the networking engine, or reboot.
$ sudo service networking restart
Using madwifi drivers
WORK IN PROGRESS
- Dell Optiplex Gx620
- WiFi card with Atheros chipset (using madwifi drivers)
- Linux MCE 810 alpha2
If you install LMCE from scratch make sure that your wifi card is NOT inserted prior to installation so that LMCE doesn't use it as the internal network interface. After LCME installation has finished, insert the wifi card.
the idea is to combine or bridge eth1 and ath0 to a new virtual interface called br0.
- -> eth0 connects to my ADSL modem (192.168.1.0)
- -> eth1 connects to my internal LAN switch (192.168.80.0)
- -> ath0 connects the wireless part of my internal network (192.168.80.0)
We'll make a copy of /etc/network/interfaces in case something goes wrong before we edit it.
mv /etc/network/interfaces /etc/network/interfaces.bck
auto lo eth0 eth1 br0
automatically initialise eth0 (external interface) eth1 (internal LAN) and br0 (our bridge interface). Keep ath0 out of this for now, we'll initialise it separately.
iface lo inet loopback
# Internet Interface iface eth0 inet static address 192.168.1.2 netmask 255.255.255.0 gateway 192.168.1.1 dns-nameservers 192.168.1.1
Fill in your own settings here, in my case 192.168.1.1 is the ADSL modem. Alternatively you can use dhcp to get the adress details from your ADSL modem.
# LAN interface iface eth1 inet manual up /sbin/ifconfig eth0 up down /sbin/ifconfig eth0 down
The internal interface, note that it doesn't get an adress assigned.
# Wireless interface auto ath0 iface ath0 inet manual up /sbin/ifconfig ath0 up
The wireless interface, again no adress details here.
iface br0 inet static address 192.168.80.1 network 192.168.80.0 netmask 255.255.255.0 broadcast 192.168.80.255 pre-up /usr/sbin/brctl addbr br0 pre-up /usr/sbin/brctl addif br0 eth1
The fun part. Finally we assign the adress for the internal LAN to the bridge interace br0 (I'm sticking here with the standard LMCE network 80.0). The pre-up will create a bridge and add the eth1 interface to it.
pre-up /sbin/wlanconfig ath0 destroy pre-up /sbin/wlanconfig ath0 create wlandev wifi0 wlanmode ap pre-up /sbin/iwconfig ath0 channel 3
This part is necessary as the atheros interface has some issues to switch ino access point mode (master mode)
pre-up /usr/sbin/brctl addif br0 ath0
After firing up the wireless interface we add it to the bridge as well.
post-down /usr/sbin/brctl delif br0 eth1 post-down /usr/sbin/brctl delif br0 ath0 post-down /usr/sbin/brctl delbr br0
Just some lines to define how to cleanly shut down the bridge: remove both interfaces and then remove the bridge interace itself
We need to set the bridge (which contains eth1 and ath0) as the new interface for the dhcpd server. Edit /etc/default/dhcp.conf as followed:
We'll use hostapd to manage the wireless part as it provides WPA encryption. I suggest that you first try to setup your network without encryption, make sure it works and then enable encryption.
Enable WPA encryption
- edit the /etc/hostapd
Set static IP adresses
It is possible to set static ip adresses manually instead of using LMCE.