askuhn's questions

I wanted to use my desktop with a wired ethernet connection (eth0) to operate my "TP-LINK TL-WN722N" USB Wifi Adapter (wlan0) as a non-adhoc (infrastructure mode) access point for my Android to connect to.

After MUCH searching, I finally found a method (spread across many websites) that does most of what I need...

Dependencies:

 hostapd
 bridge-utils

I modified "/etc/network/interfaces"

sudo gedit /etc/network/interfaces

to contain:

# This file describes the network interfaces available on your system
# and how to activate them.

auto lo br0
iface lo inet loopback

allow-hotplug eth0
iface eth0 inet manual

allow-hotplug wlan0
iface wlan0 inet manual

# Bridge setup

# for dhcp address
iface br0 inet dhcp
bridge_ports eth0 wlan0

# for static ip
# iface br0 inet static
# bridge_ports eth0 wlan0
# adapt with your network settings
# address 192.168.1.250
# netmask 255.255.255.0
# network 192.168.1.0
# broadcast 192.168.1.255
# gateway 192.168.1.1
# dns-* options are implemented by the resolvconf package, if installed
# dns-nameservers 192.168.1.1
# dns-search localdomain

### Reference ###

# Creating a Wireless Access Point with Debian Linux « Agent Oss (October 31, 2011)
# https://agentoss.wordpress.com/2011/10/31/creating-a-wireless-access-point-with-debian-linux/

My "/etc/hostapd/hostapd.conf" (which I somehow managed to put together myself)

sudo gedit /etc/hostapd/hostapd.conf

contains:

 ### Guts ###

 interface=wlan0
 bridge=br0
 driver=nl80211

 ### General ###

 ssid=____________________
 hw_mode=g
 channel=1

 ### Security ###

 macaddr_acl=0
 auth_algs=1
 ignore_broadcast_ssid=0     ## 0 visible # 1 hidden ##
 wpa=2
 wpa_passphrase=____________________
 wpa_key_mgmt=WPA-PSK
 wpa_pairwise=TKIP
 rsn_pairwise=CCMP

 ### Reference ###

 ## Created Tuesday, February 14, 2012 ## Ubuntu 11.10/12.04 ##

 # Hostapd Linux Documentation Page
 # http://linuxwireless.org/en/users/Documentation/hostapd

 # Creating a Network Bridge on Ubuntu (January 16th, 2011)
 # http://webserver.linuxportal.nl/?p=422

(I've edited out the security bits for this post)

All of that allows me to open up a Terminal and execute:

 sudo hostapd -B /etc/hostapd/hostapd.conf

to have a functioning access point that my Android and all other WiFi devices can connect to.

Aside from sharing this method with others since info for this setup is so sparse; there are three problems that would be nice to fix:

1. This configuration deactivates network manager and all of its functions. When you click it, it gives a "device not managed" message. (not essential, but a bit annoying to me)
2. This method can struggle with IP addresses from time to time.
3. I must use a terminal to turn on Wifi. (Ok for me, but not family friendly). I figured out how to make a launcher using gksu and a simple script if anyone needs one...

4. (Why can't network manager do this out-of-the-box??)

Thanks in advance! I hope all of this can help someone else; I've never written a tutorial before and know virtually nothing about networking...

Perhaps related to network bridge - without destroying network manager (among others).

Tested using Ubuntu 11.10, 12.04.