Android tethering
Contents
What is Tethering
Tethering is a way to have Internet access on your PC through your smartphone using its network connection. USB and Wi-Fi access point tethering is natively supported from Android Froyo ( 2.2 ). Older versions of the Android OS, mostly unofficial roms have this option enabled.
Wi-Fi access point
Using an Android phone as a Wi-Fi access point (using 3G) has been accessible by default since Froyo (Android 2.2) without needing to root the phone. Moreover, this method will discharge the battery rapidly and tends to cause intense heating, unlike USB. See : menu/wireless & networks/Internet tethering/Wi-Fi access point
USB tethering
Tools Needed
- Root access to the phone (for old Android versions, Froyo (Android 2.2) and beyond can do it natively)
- USB connection cable from your phone to PC
Procedure
- Enable USB Debugging. This is usually done from Settings --> Applications --> Development --> USB debugging. Reboot the phone after checking this option to make sure USB debugging is enabled (if there is no such option, this step probably does not apply to your version of Android)
- Disconnect your computer from any wireless or wired networks
- Connect the phone to your computer using the USB cable (the USB connection mode -- Phone Portal, Memory Card or Charge only -- is not important, but please note that you will not be able to change the USB mode during tethering)
- Enable the tethering option from your phone. This is usually done from Settings --> Wireless & Networks --> Internet tethering (or Tethering & portable hotspot, for more recent versions)
(The following step may not be needed. usbnet module may not be necessary, do it only if you do not see a usb0 interface in the ifconfig step)
- Load the usbnet module(if it's not already loaded). You will need root access to do that
modprobe usbnet
- Make sure that the USB interface is recognized by the system by using the following command:
ifconfig -a
you should be able to see a usb0 device listed like this (notice the usb0 device):
# ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:16:36:FA:3E:31 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:316435 errors:0 dropped:0 overruns:0 frame:0 TX packets:316435 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:22875193 (21.8 Mb) TX bytes:22875193 (21.8 Mb) usb0 Link encap:Ethernet HWaddr C2:5A:11:8D:43:F5 BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
- Configure the new network device via DHCP using the following command:
ifconfig usb0 up && dhcpcd usb0
To configure the new network device using the iproute toolkit, issue the following as root:
ip link set usb0 up && dhcpcd usb0
To stop the network sharing, issue the command:
dhcpcd -x usb0
USB tethering with OpenVPN
This method works for any old Android version and does not requires root access nor modifications in the phone (it is also suitable for Android 2.2 and later, but no longer required).
It does not requires changes to your browser; in fact transparently handles all network traffic for any PC application (except ICMP pings). It is somewhat CPU intensive in the phone at high usage rates (a 500 kbyte/sec data transfer rate may take more than 50% of phone CPU on a powerful Acer Liquid).
Tools Needed
In Arch, you need to install the openvpn package. Is is also required the Android SDK installed (which can be obtained here). In the phone, the azilink application, a Java-based NAT that will communicate with OpenVPN in your computer.
Configuring the phone connection in Arch Linux
Once you have installed the Android SDK, in order to use the provided tools your phone must be properly set up in udev and your Linux user needs to be granted rights. Otherwise you may need root privileges to use the Android SDK, which is not recommended. To perform this configuration, turn on USB debugging on the phone (usually in Settings -> Applications -> Development -> USB debugging), connect it to the PC by the USB cable and run the lsusb
command. The device should be listed. Example output for the Acer Liquid phone:
Bus 001 Device 006: ID 0502:3202 Acer, Inc.
Then, create the following file, replacing ciri by your own Linux user name, and 0502 by the vendor ID of your own phone:
/etc/udev/rules.d/51-android.rules
SUBSYSTEM=="usb", ATTR(idVendor)=="0502", MODE="0666" OWNER="ciri"
As root run the udevadm control restart command (or reboot your computer) to make the change effective. Now run in your linux PC the adb shell command from the Android SDK as plain (non root) user: you should get a unix prompt in your phone.
Procedure
Run the AziLink application in the phone and select "About" at the bottom to receive instructions, which basically are:
- You will have to enable USB debugging on the phone if it was not already enabled (usually in Settings -> Applications -> Development -> USB debugging).
- Connect the phone with the USB cable to the PC.
- Run AziLink and make sure that the Service active option at the top is checked.
- Run the following commands in your Linux PC:
- As plain user: adb forward tcp:41927 tcp:41927 (requires Android SDK installed)
- As root: openvpn AziLink.ovpn
AziLink.ovpn
dev tun remote 127.0.0.1 41927 tcp-client ifconfig 192.168.56.2 192.168.56.1 route 0.0.0.0 128.0.0.0 route 128.0.0.0 128.0.0.0 socket-flags TCP_NODELAY keepalive 10 30 dhcp-option DNS 192.168.56.1
Tethering with proxy
With this method tethering is achieved by port forwarding from the phone to the PC. This is suitable only for browsing. For Firefox, you should set network.proxy.socks_remote_dns to true in about:config ( address bar )
Tools Needed
- Root access to the PC
- Android SDK which can be obtained here
- USB connection cable from your phone to PC
- Proxoid application(free download from the Android market)
Instructions
Follow the instructions demonstrated in the following link