IPSEC Tunnel between two clouds while DirectConnect is already there?

Hi All,

I'm currently facing an issue that i'm trying to solve, and i'm kind of stuck on how to fix it. So maybe you guys have a great idea.
Situation is as follows :

We have a dual-cloud setup, AWS & Azure, connected to eachother with a DirectConnect/ExpressRoute connection for internal traffic, working fine. But the DirectConnect is limited to only 200Mbps and is used for some critical internal communication that we don't want to disturb. For a project we need to transfer some pretty massive files between the 2 clouds, so we want to setup a new connection between the 2 clouds, but with IPSEC this time.

So i created 2 machines, one on either side. Strongswan IPSEC tunnel is up and running fine, but the routing is a pretty massive issue, because both sides can route all the traffic. Example : If i'm on a machine in Azure and i ping test.internal it will resolve to 172.0.0.x, but if i do the same on an AWS machine it will also resolve to that IP.

So the question is : How do we get the routing through the tunnel setup correctly now? Any ideas or tips?