I have an issue on my Mikrotik wireless network where clients with IPSec VPNs are not able to connect to VPN servers on my network. They are able to connect when they use a different provider.
The client configured IPSec on Cyberoam devices and simply use my client’s network for connectivity and internet. While the internet works fine, the VPN is failing to establish a connection, the VPN site routers seem to think the Mikrotik router (CCR1016-12G) on the Edge of the network is their peer. So the site A gives a peer authentication error with the Mikrotik IP facing the Internet and site B gives the Internal IP of the Mikrotik. This should not be the case, Site A and Site B are peers and the Mikrotik is just transparent. The public IPs are routed and not Natted and end to end pings and traceroutes work for the VPN IPs work.
Is there some configuration on Mikrotik to allow IPSec VPN traffic to pass through? Any advice is welcome.