I am experiencing routing issues on my Cerbo GX setup and would like to confirm if this configuration is supported or if there are specific best practices to follow.
The Setup:
Ethernet: Connected directly to a Raymarine Axiom MFD.
WiFi: Connected to an onboard RUT950 router for LAN/Internet access and integration with a local Home Assistant instance.
The Problem: I am unable to ping the Cerbo’s WiFi IP address or connect to the MQTT service (Plaintext) via the WiFi interface. It appears that the Cerbo GX is struggling with routing when both interfaces are active. I suspect the device is attempting to route traffic through the Ethernet interface instead of using the WiFi gateway for LAN/MQTT traffic.
Specific Questions:
Is it intended for the Cerbo GX to handle dual-interface routing simultaneously for these different traffic types?
Are there known issues with MQTT binding to the WiFi interface while the Ethernet port is active?
What is the recommended approach to ensure MQTT/LAN traffic strictly uses the WiFi interface while still allowing the Ethernet port to communicate with the Raymarine network?
I have verified that there are no IP conflicts between the Raymarine network and the RUT950 LAN. Any insights or advice on how to configure the routing tables or service bindings to resolve this would be greatly appreciated.
As long as your WiFi and wired ethernet interfaces are on separate networks, you can use policy routing to get the packets to go where you want them. What you cannot do is have wired and WifI on the same network and then send only traffic that came in on the WiFi out the WifI and traffic that came in on the wired, back out the wired. There’s a single “default gateway” for each subnet, you can’t have two.
You could create some tricky firewall based rules that looks at the packet headers and tries to route them around, but that’s not supported by the Cerbo GX.
What you’re probably looking for is to bond the two interfaces together, not treat them as separate clients of the same subnet.
Let me/us know what you’re trying to do and I’m sure others in the community can help.
Thank you for the clarification regarding subnets and default gateways. I have confirmed that my Ethernet (Raymarine) and WiFi (RUT950) interfaces are indeed on separate subnets, which seems to align with your recommendation.
Given that I am currently accessing the Cerbo GX remotely via a VPN to the RUT950 LAN, I am trying to resolve the routing priority without needing physical access to the boat.
To follow up on your point about policy routing and the limitations of the Cerbo GX:
Is there a supported way to manage these routing preferences remotely? I would prefer not to modify low-level configuration files (like connman or routing tables via SSH) if they risk being overwritten or causing system instability during updates.
Regarding your suggestion of “bonding”: Is interface bonding (or bridging) natively supported or recommended within Venus OS for this specific use case (Ethernet-to-MFD + WiFi-to-LAN)?
Command-line management: If I were to use SSH/CLI as a last resort, are there specific connmanctl commands that are “safe” to use, or is it strictly advised to avoid this entirely?
My goal is simply to ensure that all MQTT and management traffic uses the WiFi interface as the primary path, while keeping the Ethernet port dedicated only to MFD communication.