The latest iOS version is 7.0. Have you updated to iOS 7? If not, you can go to "Settings" - "General" - "Software updated". Follow the onscreen instructions to download and install iOS 7. Most of apple fans have updated to iOS 7 according to the latest data announced by Apple.inc. I found many people are searching for how to setup L2TP IPSec VPN on iPhone, iPad or iTouch. Whatever you are using iPhone 4/4S/5/5S, iPad 2/3/4/5/mini/mini 2/air, or iPod touch 2/3/4/5. After read this article, you will know how to configure L2TP IPSec VPN on iOS.
In Settings, tap General, tap VPN, tap add VPN configuration. Choose L2TP, then fulfill description, account, server, password and secret blank areas. You should input account, password, server address and secret provided by VPN service provider. If you do not know how to set up IPSec VPN on iOS by reading instruction sentences above, I will guide you setp by step with pictures.
I know many users love to test VPN services on iPhone before purchase, so it's my pleasure to introduce a VPN service provider which is providing free trial VPN account. It is FlyVPN. Also I will post instructions about how to set up free trial IPSec VPN on iPhone, iPad, iTouch.
1: Go to "Settings" - "General" - "VPN" - "Add VPN Configuration".
2: Fulfill blank area as photo.
Description: Input whatever you like.
Server: Register an account and access http://www.flyvpn.com/User/VpnServers to check server address in trial accounts.
Account: vpnu or vpnc.
Password: Get latest VPN password from http://www.flyvpn.com/freetrial.
Secret: vpnserver (9 lower case letters).
Users can test 30 countries VPN servers with FlyVPN trial VPN account. Know more free trial VPN server locations here: http://bit.ly/1apHG63.
I have wrote an article about how to setup PPTP VPN before, so you can access http://freeusavpn.blogspot.com/2013/02/tutorialhow-to-setup-pptp-vpn-on-iphone.html to configure PPTP on iPhone.