All computers and mobile devices such as iPhones connect to the Internet using an Internet protocol (IP) address. This unique code identifies your system and allows packets to be routed to and from your iPhone. Typically an IP address is assigned to a system such as an iPhone dynamically. It may be necessary to force your iPhone to change its assigned IP address. Perhaps you are experiencing trouble with your Internet connectivity, or you may wish to disguise the fact that you are repeatedly connecting to a remote site.
Disable Wi-Fi connectivity on your iPhone to ensure that you are connecting to the Internet over a mobile data connection. The iPhone will always prioritise Wi-Fi traffic higher than 3G or Edge network traffic. Open the Settings app and select the Wi-Fi menu to find the toggle switch that allows you to disable Wi-Fi on your iPhone.
Ensure that you have data connectivity by looking at the very top of your iPhone display for "3G" or "EDGE." You can verify this by opening the mobile Safari app and attempting to connect to a website.
Connect using the mobile Safari app on your iPhone to a website that reports back your external IP address. One such resource is offered by Tech Den (www.techden.com/myip).
Make a note of the IP address that is reported back to you.
Enable Airplane Mode on your iPhone and then turn it back off. You can do this under the Settings app on your iPhone. Airplane Mode is the very topmost menu item under "Settings."
Connect to the same website as earlier using Safari on your iPhone. Compare the addresses. If they are different, you have successfully changed your IP. If they are the same, you may need to enable Airplane Mode on your iPhone and leave it on for a few minutes before turning it off.
Connect with the Safari app on your iPhone to a website that reports your external IP address, for example Tech Den.
Go into the Settings app on your iPhone and then select the Wi-Fi menu. Press the blue arrow to the far right of the network name to which your are currently connected. The network to which you are connected will display a check mark next to it.
Make a note of the IP Address reported under the Dynamic Host Connection Protocol (DHCP) tab for your current network.
Turn off Wi-Fi on your iPhone using the toggle button within your Settings app and then turn it back on. This will force you to disconnect and reconnect to the Wi-Fi DHCP server.
Check your IP Address under the DHCP tab of your Wi-Fi network within the Wi-Fi Settings on your iPhone. If it is different, you have forced a new IP address.
Check your external IP address using the website you used earlier. Your internal DHCP address can change but you may still see the same external IP address. This is because many Wi-Fi networks use Network Address Translation, or NAT, to hide a network of systems behind a single Internet address.
Turn off Wi-Fi on your iPhone and connect to the Internet using your mobile data plan. This will ensure that you are connecting with a different IP address. However, in some cases, you may not be able to connect to a mobile data network or may wish to preserve your data usage.
Connect to the Internet using a different Wi-Fi network. If you are unable to connect with a mobile data network and you have been unable to change your external IP address due to NAT issues, the only way to change your iPhone's IP address on the Internet is to connect using a different Wi-Fi network. Go to a coffee shop or friend's house and use that Wi-Fi.