FireBrick Road Warrior iPhone iPad iOS8
Currently (June 2015) iPhone and iPad devices need a 'profile file' to be generated and then sent to the device. This file contains the IPsec details. FireBrick has a bash script that can be used (on a linux or windows machine with cygwin) to generate the gile.
make-profile tool
You can download the script from:
http://www.firebrick.co.uk/tools/make-profile
iPhone profile
Each iPhone needs a profile file specific to that user. Once created you can email this, or make a web link to it, and the iPhone will recognise it and allow it to be installed. Let's call it fred.mobileconfig for our user called fred as in the above example config.
./make-profile SERVER=IP-of-server LOCALID="Fred's iPhone" CA=ca-cert.pem SERVERID=server.example.com USERNAME=fred PROFNAME="Office VPN" VPNNAME=FireBrick fred.mobileconfig
Note that the SERVERID must match the FQDN entry used when making the server certificate, and hence the local-ID in the config for the connection.