Reverse-Tethering the iPhone
This article is probably not for the 95 percent of you who are reading this. We are not going to describe how to obtain Internet access on your PC via a tethered iPhone connection; instead, we are going to describe the reverse—how to get the Internet on your iPhone via a tethered PC connection. Why would you want to do this when the iPhone already has access to the EDGE network? Well, there are several possible reasons for this.
First, the EDGE network is notoriously slow. So, if your PC is connected to a faster Ethernet network and you want to access the Internet on your iPhone, the following procedure will give you a fast and reliable link to the local area network. Second, if you are interested in researching the requests made by the iPhone to Internet-based resources, there is really no out-of-the-box method for controlling the data flow—unless you set up a proxy and pass all your HTTP traffic through it. The following method does just that with the assistance of the Burp suite, a popular tool for security researchers and web developers. Finally, there is a small and growing group of iPhone owners out there who are not on any phone network. As a result, unless they have a wireless network available to them, they cannot access the internet. The following steps will get their iPhone online and also give this group of users the power to tweak their data as previously mentioned.
Setting Up the Wi-Fi Link
The following instructions assume you have a laptop or PC with a wireless network card. You do not need to have a wireless router/network as we will be creating our own ad-hoc network to establish a link between the PC and iPhone. Once the wireless connection is created, we will then describe how to route all Internet traffic through the wireless ad-hoc connection, and relay it through the PC out to the Internet.
To set up the wireless ad-hoc connection on the PC:
- Open Wireless Network Connection Properties, select the Wireless Networks tab, and click the Add button.
- Type iPhone in the Network Name (SSID) field.
- Check the This Is a Computer-to-Computer (Ad-Hoc) Network; Wireless Access Points Are Not Used checkbox.
- Click OK.
- Click the Advanced button.
- Select the Computer-to-Computer (Ad Hoc) Networks Only option.
- Click Close and then click the General tab.
Next, configure the TCP/IP settings with static addresses:
- In the Wireless Network Connection Properties window, select Internet Protocol (TCP/IP) from the Items list and click the Properties button.
- Select Use the Following IP Address and enter 10.0.0.1 in the IP Address field.
- Enter 255.0.0.0 in the Subnet Mask field.
- Leave the remaining fields blank, and click the OK button.
Now we have to configure the iPhone to connect to the 802.11 wireless ad-hoc network. To do this, power up the iPhone and add the necessary settings:
- Press the main Application button.
- Select Settings, then select Wi-Fi from the menu.
- Select the Other option, enter iPhone into the Name field, and press the Join button.
- Once the iPhone network shows up in the Wi-Fi Networks page, press the blue arrow to enter the TCP/IP settings.
- Select the [Static] button and enter 10.0.0.2 in the Address field.
- Next enter 255.0.0.0 in the Subnet Mask field.
- Scroll down the settings page and select the Manual button.
- Enter 10.0.0.1 in the Server field and 8080 in the Port field.
- Tap the Wi-Fi Networks button at the top and select the new iPhone connection to join. It may tell you the connection is not available, but this should start the association/authentication process and result in a connection.
At this point, the hardware for both the PC and iPhone are configured for the ad-hoc connection. Once the settings are saved, your PC and iPhone should establish a wireless connection automatically.