RUT200 IPsec over DynDNS

Greetings community,

I have issue regarding IPsec and DynDNS.
I have two RUT200s with SIM cards. I am testing L2TP over IPsec connection between them.
First RUT gets IP address over DynDNS. I successfully create L2TP connection using domain name of server in L2TP client. When i try to add IPsec connection with domain name setting on client’s IPsec , it doesn’t work, but if I set IP bound to domain name, connection works. Why?

Solved: In IPsec setup for server i needed to set local identifier (hostname from DynDNS).
Also enable bind to L2TP in settings.