Security is an important topic for the Internet of Things, and there are several considerations to secure device identity. A good practice is to use secure protocols (such as TLS or DTLS) for transmitting any sensitive information over the network and to ensure that passwords and other sensitive information are securely stored.
This article will provide an example of using X.509 client certificates for connecting to Azure IoT, using the Nordic Thingy:91 platform. The certificates are securely loaded directly to the device, so they are not exposed in the device firmware.
Using certificates allows a hierarchy of trust to be established, allowing system owners to delegate certificate management to third parties while retaining control of the root trust.
The article also covers the usage of IPv6, and accessing IPv4 servers from the Telstra IoT network, running in IPv6-only mode and using NAT64.
Continue reading Device Authentication with Nordic Thingy:91 and Azure IoT Hub(22 min read)
Network address translation 6-to-4 (NAT64, RFC 6146) is a transition technology that can be used, in conjunction with DNS64 (domain name system 6-to-4, RFC 6147), to replace NAT44 in dual-stack networks, and allowing support of IPv6 only devices.
Dual stack is a common deployment solution for adding IPv6 for both consumer and corporate networks, although IPv6-only is becoming more common, with the typical guidance being "IPv6-Only Where You Can, Dual-Stack Where You Must"
Even if you are still stuck in dual stack, it still makes sense to use some of the IPv4 as a Service technologies, such as NAT64 and DNS64, which have the upside of allowing you to support IPv6 only devices, and no downside. As an additional benefit, you also get valuable experience in IPv6 systems.
The cost is that you need to have infrastructure that supports NAT64, either provided by your ISP, or from your own networking equipment/router. This is not as much an issue for DNS64, as public DNS64 is available, e.g. Google.
If your network supports it, look at implementing NAT64 + DNS64 today; if it does not, contact your equipment provider to find out when they will support this important technology for IPv6.
Continue reading Running NAT64 in a dual stack network(5 min read)
Thread is a mesh networking stack running on 6LoWPAN (IPv6 over Low-Power Wireless Personal Area Networks) over IEEE 802.15.4 radios. To connect to the broader network, a Thread Border Router is required, which acts as a gateway between the Thread mesh radio network and upstream networks.
Thread, especially when used with Matter, is an important development for home automation, however the technologies also have commercial applications. The initial commercial focus of Thread is for smart buildings.
The networking layer sits between the underlying physical network, and the application layers on top.
Matter is an application protocol for device automation that runs on top of Thread (and also WiFi), with Bluetooth used for device commissioning. Matter 1.0 was also released in October 2022 and is supported by major home automation vendors (Google, Amazon, Apple, and Samsung), but can also be used in commerical deployments.
When provisioning a Matter device to a Thread mesh, Bluetooth is used for the initial provisioning and sets up both the connection the the Thread mesh and registration in the Matter Hub. One important aspect of Matter is multi-admin, allowing one device to be controlled by multiple hubs.
The layered approach means Thread can be used by itself, providing mesh networking for smart buildings using other protocols, or in conjunction with Matter.
The article also looks at setting up a OpenThread Border Router for testing, and shows provisions a Matter test device to the Thread mesh.
Continue reading Smart Buildings — Running an OpenThread Border Router(18 min read)
M5Stack produce a suite of pilot-suitable modular IoT devices, including the Atom DTU NB-IoT. The NB-IoT DTU (Narrow Band Internet of Things - data transmission unit) comes in a small 64 24 29mm case with a DIN rail clip on mounting and support for RS-485 including 9-24V power (or USB-C power).
The kit base has a SIM7020G modem and the ESP32-based Atom Lite (which also supports WiFi) is included with a very resonable price. The device has built in MQTT, supports secure public certificate TLS connections, and supports IPv6.
While the physical unit is ready for pilot deployment (and the M5Stack website has several commerical deployment case studies), there is no pre-written firmware for the device, so some up front development is needed.
As well as reviewing the strengths and weaknesses of the device, I will also provide some sample code for a proof-of-concept using an Env III environment sensor to transmit temperature, humidity, and air pressure to an MQTT test server using MQTTS (with server certificates), over IPv6, over NB-IoT.
Continue reading M5Stack Atom NB-IoT device with secure MQTT over IPv6(20 min read)
MQTT (originally Message Queuing Telemetry Transport) is an important protocol for IoT that has been widely adopted. Devices deployed to the field may be connecting to existing MQTT endpoints, however you may also want to deploy your own MQTT server for testing purposes.
This article shows you how to deploy an Eclipse Mosquitto MQTT server onto Azure, configured for secure connections (MQTTS, which is MQTT over TLS), accessible over the internet, and including support for both IPv6 and legacy IPv4.
First we will configure a network in Azure, then deploy the server, and then test the deployment.
The instructions below show the individual commands, but if you want a quick start then full scripts, with automatic parameters, are available on Github https://github.com/sgryphon/iot-demo-build/blob/main/azure-mosquitto/README-mosquitto.md
To deploy the network and then server components via the scripts:
az account set --subscription <subscription id>
$VerbosePreference = 'Continue'
Read on for the full details.
Continue reading Deploying a secure MQTT test server on Azure with IPv6(15 min read)
It is important to ensure your IPv6-only docker server is secure.
First configure your firewall to allow secure shell (SSH), port 22, so that you can maintain your remote connection.
Then turn on your firewall with default deny incoming and default deny routing rules.
This ensures your server is secure-by-default, and only then should you allow routing to the specific containers and ports that you want to expose.
My server runs Ubuntu, so these instructions are based on the Uncompliciated Firewall (UFW), but similar considerations apply to other platforms
Continue reading Securing your IPv6-only docker server(8 min read)
There are very simple instructions for installing Ubuntu on a Raspberry Pi, simply downloading the Imager and then pick the OS (which it will download for you, I used Ubuntu Server 20.04 LTS), and write it to the micro SD card for your Pi. https://ubuntu.com/tutorials/how-to-install-ubuntu-on-your-raspberry-pi
The image is pre-configured for DHCPv4 using the wired Ethernet connection, with alternative instructions for getting it setup with Wi-Fi, but without mention of IPv6, which is now used by 30-35% of the Internet.
Here are instructions for setting up Ubuntu on your Raspberry Pi up with IPv6 only.
Continue reading Ubuntu, Raspberry Pi, IPv6 only(6 min read)
IPv6 support for Azure VNets is currently available in preview (https://azure.microsoft.com/en-us/updates/microsoft-adds-new-features-to-ipv6-support-for-azure-vnets/).
Most of it is available via the Azure Portal, but I found allocating an IP config to a network card had to be done via the shell.
Here are the steps I did to test:
Continue reading IPv6 virtual networks on Azure(2 min read)