@Somnus Thank you so much for your reply! I tried OpenVPN as an alternative. But it seems like OpenVPN is only possible in a client-to-site configuration so that only one site can reach the other but...

Hi there, I have a problem with my VPN network between two sites. I have created an IPSEC VPN between two Er605 Routers but only one router on one site is reachable but I don't get the point why....