Ncat in Embedded DevOps: A Practical First-Response Tool
In my current company, I manage the DevOps processes for embedded projects. With the CI/CD pipelines we built on Jenkins, we transfer the builds to the devices, run test automations, send the logs to the related teams via Teams, and also notify the teams after each Jenkins build. In short, I try to make every step coming from the device as automatic and trackable as possible.
At one point in these processes, I needed to send data to the device over the network. Since the device has a UART connection, I looked for a way to create a bridge between the network and UART, and I discovered that Ncat could be useful for this. I did not see Ncat only as a tool for this specific case. I also looked at it as a simple and fast way to do basic network tasks. I tried to explain, based on my own experience, how practical it can be for things like sending messages between two machines, transferring files, testing ports, or creating a temporary tunnel.
What is Ncat in short?
Ncat is a modern network tool developed by the Nmap project. We can think of it as a more advanced and safer version of the classic Netcat (nc). Ncat is very useful both in embedded systems and in DevOps processes. Because it gives direct access to the network layer, it is ideal for quick diagnosis, testing, and temporary solutions — especially on devices with limited resources and in complex infrastructures.
Use in Embedded Systems
Embedded devices (IoT, industrial controllers, edge devices, etc.) usually have limited storage and processing power. Thanks to its lightweight design, Ncat is useful in these situations:
- Debug over the network instead of serial port When UART access on the device is difficult, you can open a simple TCP listener with Ncat and get logs or a command line remotely. Example:
ncat -l 4444 -e /bin/sh- Firmware or log transfer To pull a log file or configuration from the device, or to send a new binary:
# On the device (receiver)
ncat -l 9000 > firmware.bin# On the host machine (sender)
ncat device-ip 9000 < firmware.bin- Simple health check and port test You can quickly check if a specific port on the device is open or if a service responds.
- Temporary tunnel / relay If the device is behind NAT, you can create a simple reverse tunnel with Ncat to reach it from outside (especially during development).
Note: SSL support is not always active on embedded systems. If possible, prefer encrypted connections with — ssl, or use it only on secure networks.
Use in DevOps and Infrastructure Management
For DevOps teams, Ncat is a “quick and dirty” but effective diagnostic tool:
- Service availability test To check if a port is really listening between Kubernetes pods, containers, or remote servers:
ncat -vz target-host 8080- Temporary proxy or port forwarding When you want to quickly redirect a service to another port or watch the traffic for debugging:
ncat -l 8080 --sh-exec "ncat real-service 80"- Log and file transfer (in CI/CD pipelines) You can use it as a light alternative to scp/rsync to quickly move build artifacts or logs between two machines.
- Container and network debug It is ideal for testing a pod’s network connection in Docker or Kubernetes, checking DNS resolution, or starting a simple echo server.
- Encrypted reverse shell / debug session For troubleshooting on secure networks:
ncat --ssl -l 443 -e /bin/bashPractical Tips
Conclusion
Ncat is not designed to be a full monitoring tool or a permanent solution. However, it is a very practical “first response” tool for quick communication with devices during embedded development and for diagnosing network problems in DevOps processes. It shows its value especially in resource-limited environments and in moments when you think “something went wrong, I need to check it right now.”
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Security should always come first. In production environments, use it with encryption ( — ssl) and access control ( — allow) whenever possible.
