L2TP VPN with eth0 DHCP IP adresss from ISP

Hi,

I am using this tutorial:

https://help.ubnt.com/hc/en-us/articles/204950294-EdgeMAX-L2TP-Server

At the end I get the following error;

l2tp vpn configuration error ipsec did not start

Google tells me because this is because my ISP delivers a dynamic IP.

I would like to use L2TP VPN because PPTP is not supported in Mac OSX Sierra.

What should I do? Thank you!