I need interconnect 2 LAN via Internet. One end is connected over ADSL modem (static public IP is ending in modem) - router have private natted IP. ROS v3.0 support IPsec NAT-T now. How setup tunel on both routers?
Use 3.0 on the MikroTik end, it should work without any configuration (IPSec configuration is required of course).
For 2.9 you may add accept rules to nat table before masquerade, it should work too.