Have to reboot Hub

Our user Ben Watkins emailed because he was unable to post his question here, so I'm posting it for him - it is:

“I have been using the Ayrstone HUB2T for a number of years and for some reason I have to reset the hub periodically by removing the cable and plugging back in.”

The Hubs (and Receivers, IndoorHubs, and Bridges) are little computers running Linux; as such, there are extremely reliable and resilient. They're also remarkably simple - they're much less complex than your router, never mind your phone or laptop. They typically run uninterrupted until the power goes out, although they do monitor your network and take action, including rebooting themselves, if something goes wrong.

But the Hub can provide no better service than the network it's plugged into. There is a common misperception that the AyrMesh system is separate from your router, but exactly the opposite is true. The AyrMesh network (Hubs, Receivers, IndoorHubs, etc.) is, essentially, transparent to the router - anything connected to the Hub looks to the router as if it is connected directly to the port on the router that the Gateway Hub is plugged into. The AyrMesh network doesn't route, filter, or alter the data going through it - it just passes the along.

There are several conditions that can cause the router to freeze, but there are two common ones: network loops and IP address conflicts.

A network loop occurs any time the data on the network can arrive at a device on the network and then re-enter the network through another route. It requires a device that has two interfaces connected to the network at the same time. We commonly see them here in the lab when someone connects a printer or WiFi camera via WiFi when it is already connected via Ethernet, but, especially with the prevalence of "Internet of Things" (IoT) devices, it can be as subtle as having two "Gateway" devices for a low-power network (e.g. LoRa or Zigbee) connected to the network and having the devices between them able to “close the loop.”

IP address conflicts occur when two devices on the network have the same IP address. This commonly happens in one of two ways:

1. A device on the network is pre-configured with a "static" IP address that falls within the DHCP range of the router. Everything works just fine until the router assigns that IP address to another device, and then there are two devices with the same IP address
2. Someone places a second router on the network with the same IP address as the main router and/or an overlapping DHCP range. Again, everything works just fine for a while until either the main router "sees" the secondary router at its IP address, or the second router assigns an IP adddress to a device that's connected to it that's the same as an IP address the primary router has assigned to a different device.

Modern routers SHOULD be able to prevent IP address conflicts, particularly for the first case, but, unfortunately, most run such old firmware that they don't.

Two tips: first, for devices like IP cameras that have to always get the same IP address, use DHCP reservations instead of pre-configured static IP addresses, and, second, never put a second router on a network unless you REALLY understand IP subnetting.

Thanks go to Ben for bringing this up. Perhaps this belongs in the FAQ, too.