I am posting this because this functionality is not available in default Ubuntu 12.10/13.04 installations. Creating a wireless hotspot (infrastructure WPA2 Security) is required to share internet connection from a Ubuntu Machine to Android/Windows powered devices or iPhones.
1. To Install the ap-hotspot script (GUI for this script is not available yet), add the following PPA:
The following command is required only if you have Ubuntu 12.04 or earlier releases:
sudo add-apt-repository ppa:nilarimogard/webupd8
sudo add-apt-repository ppa:network-manager
Update the repository informations and install the "AccessPoint-Hotspot script":
sudo apt-get update
sudo apt-get install ap-hotspot
2. After the installation, either disable the firewall (if you are comfortable enough with no firewall) using gufw or firestarter, OR change the firewall rules to allow traffic for the following two services:
3. A first time configuration can be done on Ubuntu machine by issuing the following command in the linux terminal:
sudo ap-hotspot configure
This configuration will ask for hotspot name you want to create, your LAN interface name, your WLAN interface name and the password (10 characters) etc. The interface names can be found by clicking network manager icon, and then clicking on 'information'.
4. Start the hotspot on Ubuntu machine:
sudo ap-hotspot start
The hotspot is now active and ready to go. Turn the WiFi ON on your Android device/ Windows Phone/ Mac device and your device will show your 'hotspot name' that you had chosen during first time configuration (step 3). Tap on the name of hotspot to connect and enter the required password that you had set during configuration in step 3 above.
5. This hotspot can be stopped by using the command:
sudo ap-hotspot stop
Please feel free to discuss/share your experiences/troubles....
This guide works with Ubuntu 12.10/13.04 and other derivatives of Ubuntu like Kubuntu 12.10/13.04, Xubuntu 12.10/13.04 or Zorin OS 7. Haven't checked yet on Linux Mint.
AN UPDATE (#1)
The network manager in default Kubuntu 13.10 installation has inbuilt support for Access Point mode.
Just go to "Edit Connections" on the tray icon in the plasma desktop,
Select "Add" then select "WiFi(Shared)" connection,
Select "WiFi tab, mode = AccessPoint",
Select "WiFi-Security tab, Security = WPA & WPA2 Personal and give any password" and save the connection.
That is all, you should be done!