ipsec

https://howto.lintel.in/configure-ipsecl2tp-vpn-clients-linux-cli/ https://www.digitalocean.com/community/tutorials/como-configurar-un-servidor-vpn-ikev2-con-strongswan-en-ubuntu-18-04-es https://kifarunix.com/how-to-configure-ipsec-vpn-using-strongswan-on-ubuntu-18-04/