Problems with NAT, I need to disable it.

RouterOS General
1

I inherited a RouterBoard RBD53iG-5HacD2HnD configured as a DHCP server with an active hotspot. From what I understand, the captive portal is accessed via a VPN. The issue is that I now need to disable NAT because the RouterBoard will be directly connected to a Huawei L3 switch that handles routing, and NAT must be performed by my firewall. However, when I disable NAT masquerade, the VPN no longer establishes, and I can’t access the captive portal. On the Huawei switch side, the return route is correctly configured. Additionally, the gateway for the 172.29.0.0/16 subnet assigned to the LAN is handled by the RouterBoard, and my switch’s return route points to the WAN IP of the RouterBoard (10.10.3.1).

I have networking knowledge, but I’m struggling to understand MikroTik. The system integrator managing the captive portal is unable to find a solution.

Thank you for your help.

2

If something doesn’t work after disabling NAT, it’s a routing problem.
You should know the IP address of the portal and check what traffic the VPN carries. To recognize this Use /tool/torch on the vpn interface when it is running…

3

Or better yet, export the config of the router and post it here since I’m expecting to see some firewall/NAT rules added to the hotspot chain system by the integrator that affect the VPN

/export file=anynameyouwish (minus sensitive info like public IPs, serial number, passwords, etc.)