WisGate Edge Lite 2 failover to cellular when specific port is blocked

LPWAN Industrial Gateways / Concentrators
1

Hi everyone,

I have a WisGate Edge Lite 2 (RAK7268) with the cellular add‑on and I’m trying to get the gateway to fail over from Wi‑Fi to the built‑in cellular backhaul if a firewall upstream is blocking the port we use to reach our server. In our case, the server listens on port 8887.

The service on port 8887 is a WebSocket endpoint, so I’m not testing a standard HTTP page. I just need to verify that outbound TCP 8887 connectivity is available (the WebSocket can be reached) rather than ports 80 or 443.

The “Tracking” section under Ethernet settings allows me to choose ICMP or HTTP and to set a target hostname, reliability, ping count, timeout, etc., but when I choose HTTP, I assume the gateway only does a basic curl to port 80 or 443. I don’t see any way to specify a different port for the health check. Here’s what the configuration page looks like for reference (image omitted here but it’s the standard failover HTTP test with options).

With a firewall rule that blocks TCP 8887 but still allows general web traffic, the link check succeeds and the gateway never triggers the cellular failover. Is there a way to configure the HTTP check to use a custom port or another method to detect that a specific service is unreachable? I’d prefer not to rely on ICMP if possible, since ping replies can be allowed even when the service is down.

Thanks for any guidance!

2

Hello Pikard,

The failover is based on ICMP and HTTP tracking, as you already know. It is for general connectivity, and not to track specific connections, like you want for the Basics Station forwarder.

We can provide a workaround with a watchdog function that will check the health of port 8887 at the desired IP or URL and will change the priority of the interfaces, which will lead to a change of the used interface, in your case, from Wi-Fi to Cellular.

Note that the Priority should be 1. Wi-Fi, 2- Cellular, 3- ETH

watchdog.tgz (1.1 KB)

Download & deflate the file watchdog.tgz and then add the file watchdog.sh to /mnt/mmcblk0p1/ (store the file into the SD card manually or copy & paste it with vim)

Make it executable and add a cron job that will call it every 1 minute:

chmod +x /mnt/mmcblk0p1/watchdog.sh
echo "* * * * * /mnt/mmcblk0p1/watchdog.sh" >> /etc/crontabs/root
/etc/init.d/cron restart

Now it should fall to cellular once the 8887 on the IP/URL set is not accessible over Wi-Fi.

Note that this is a workaround and we can not guarantee it will work in the long run.