The roadwarrior carol sets up a connection to gateway moon.
carol uses the Extensible Authentication Protocol
in association with the Authentication and Key Agreement protocol
(EAP-AKA) to authenticate against the gateway. This protocol is used
in UMTS, but here a secret from ipsec.secrets is used instead of a USIM/(R)UIM.
Gateway moon additionally uses an RSA signature to authenticate itself
against carol.