IPSEC Server requires public IP and make sure its services port UDP 500&4500 can work.
IPSEC Client just needs be able to access network.
IPSEC Server and Client should be with different LAN segments.
IPSEC Server Configuration
Authentication use PSK
IPSEC Client Configuration
IPsec Gateway Address should be IPsec server's public IP.
IKE parameter should be the same as the server
IPSEC Server Status
IPSEC Client Status