Google site:astaro.org Anyconnect - the first article will tell you that it doesn't work and it provides you a link to a StrongSWAN post that the Cisco EULA prohibits the use of the Anyconnect client with other VPN servers.
Cheers - Bob
Sophos UTM Community Moderator Sophos Certified Architect - UTM Sophos Certified Engineer - XG Gold Solution Partner since 2005