I was shocked as my iPad VPN can’t establish the connection after upgraded to iOS 4.3 latest version.First i thought some setting got error but still the same after re-enter the value setting,then i try to downgrade to iOS 4.2.1 version and the weird thing is all the VPN can connect smoothly.I try to connect my iPad to VPN in any manner yesterday and finally got the solution.
Actually there are a lot of discussion in Apple forum regarding VPN can’t connect after upgrade to iOS 4.3 issues.As far as i know Apple iOS devices wireless adapter is the worst compare with others mobile device,i try all the suggestion mentioned in forum but can’t work.lastly i have to use DMZ host feature in wireless router setting to solve VPN connection problem.
DMZ host feature is allows one local host to be exposed to the Internet for a special-purpose service such as Internet gaming or videoconferencing,we can use this feature to assign a special IP address for VPN connection.Below i use Aztech wireless router as example how to set DMZ host feature.
First must enable PPTP and IPsec connection in wireless router setting,then in DMZ option enable ‘current DMZ status’,IP address column follow your iOS device IP address ( tab the wireless network in iOS device,the IP address show under DHCP ),then click ‘Save’.That all.
Now you can establish VPN connection with your iOS device.
Seem this is a bug in wireless connection.