Does iOS support IPsec IKEv2?
If not, is there any way to get IPsec IKEv2 working on iOS?
I do not believe the built-in Apple VPN client supports IKEv2 on either the Mac or iOS devices. This is because certainly on the Mac - including Mavericks 10.9.1, and I believe also iOS the VPN client is based on the open-source Racoon software which does not support IKEv2.
There is a Racoon2 see http://www.racoon2.wide.ad.jp/w/ which does support IKEv2 but that is not what Apple include.
Cisco AnyConnect client for iOS and Mac does support IKEv2.
IPsec IKEv2 is not supported on iOS by Apple.
IPsec that iOS supports is
Cisco IPSec (notice that it even has a different capitalisation), according to the link from bmike ♦, the
Authentication methods section, iOS basically only supports several
IPSec Xauth authentication methods, which are an extension to IKEv1, and are incompatible with IKEv2.
iOS 9 now has a UI for IKEv2 VPN.
Yes. Since IKEv2 was defined in 2005, you'd be hard pressed to find an IPSec implementation that doesn't run v2 these days.
The best documentation I've found for iOS and VPN is here from apple:
Cisco's documentation says their AnyConnect 3.0 has a feature of IKEv2 on iOS.
If you are asking about Mac OS X built-in IPsec client, it's easy to verify that racoon is used. Just open Console and check system logs from the time when you use the IPsec client:
2/22/14 8:05:38.649 PM racoon: Connecting. 2/22/14 8:05:38.650 PM racoon: IPSec Phase 1 started (Initiated by me). 2/22/14 8:05:38.652 PM racoon: IKE Packet: transmit success. (Initiator, Main-Mode message 1). 2/22/14 8:05:38.652 PM racoon: >>>>> phase change status = Phase 1 started by us
Racoon (v1) has certain limitations like no IKEv2 support and no split-tunneling.
iOS 8 now support native IKEv2 VPN.