I succeeded to use IKEv2 with strongswan on linux. I didn't try with another client. But here is the steps I followed : - Create a CA certificate and a client certificate and key. - Put on the SSLVPN box the CA certificate in the section configuration -> certificate -> Trusted client certificate - I created a new authentication server as a certificate server. - I created a new Realm using this server for authentication and selecting a role based on userAgent (IKEv2) or the username. - I check IKEv2 in the role used for these users - I choose the new-created realm in configuration -> IKEv2. But if anyone succeeded to authenticate the user with username/password, I'm interested... ... View more