VPN behind dsl router

Hello,

I want to create vpn ipsec tunnels between MK which are behind of DSL routers.
I tried a lot of combinations to make it work, but I can, so my question is if it is really possible to do without changing DSL router configuration (I can not change its configuration into bridge mode).

Thanks in advance

In case you have public/routable IP address after VPN router, there should not be any problems to establish IPSec between these routers.