HI ,
I was able to succesfully connect main l2tp peer and PURE iPSEC CISCO with preshared key 
,but problem is when i want to use both peers i get unknown phase negotiation problem L2tp/IP overrides the IPSEC policy ,also policy how to get setup with IPSEC so the question is is they can work with both peers activated,
Also i managed to make IKEv2 connection with strongswan on Android but when i connect another smartphone the connection randomly connects and disconects how i can make the connection stable,for multiple client using same signature
Send me some good tutorial for PURE IP SEC Site-To-Site with both public dynamic address interconnection between 2 ROS mikrotik beasts ,i think IPSEC no Lt2p is best one and standard in industry,
Thanks for help