I'm using an RV042 as a sort of internet gateway router for strictly a range of public IP addresses. It interfaces with a fiber internet feed, somewhat like a modem, providing the path for all the other public internet addresses we're assigned by our ISP. This is in Router mode so no NAT.
We have 3 VPN devices that are managed by 3rd parties; each with their own public IP address.
I find that if I Enable the RV042 firewall, the 3rd party managers cannot access their VPN device that's at our site. This is true even if most of the firewall functions are disabled.
I've attached a screen shot of the firewall settings when they are Disabled. If I change *nothing* else but simply Enable the firewall top setting, the 3rd party managers cannot access their VPN device downstream.
The documentation for the RV042 in this regard is pretty thin. I'm hoping that someone who *knows* how it works or what is happening might shed some light.