All the updated iOS versions have IKEv2 protocol for VPN connection, follow the below steps to configure VPN on your iPhone or iPad using IKEv2
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Click on Settings to open the settings menu and click on General, under General you will find the VPN option
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Click "Add VPN Configuration"
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The type selected should be IKEv2 and following details needs to be added:
​Description: Name of your choice
​Server: The server address that you wish to connect to. Refer http://network.limevpn.com/ for the server list
​External ID: The same server address that was mentioned under "Server"
NOTE: In older iOS versions, you might see "Remote ID" instead of "External ID"
​Local ID: Leave it blank
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Authentication:
​User Authentication: Username
​Username: LimeVPN Username
​Password: LimeVPN Password
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After adding all the details, click on Done
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Under VPN Configurations,  to connect, click on the radio button besides the VPN profile that was created.
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