NetAlertX on Ubuntu 24.04 LTS | cloudimg
by cloudimg
Know every device on your network, and when that changes
NetAlertX is an open source network presence scanner and asset discovery framework. It sweeps the subnet it is attached to on a schedule, keeps an inventory of every device it has ever seen, records a presence timeline for each one, and raises an alert when a new device appears or a known device stops answering.
It answers a question most networks cannot answer honestly: what is actually on this network right now, and what changed? Devices are enriched with name resolution and tracked over time, so the inventory reads as equipment rather than as numbers. Alerts reach you through the channel you already use, from email and webhooks to MQTT, ntfy, Telegram and Apprise.
This cloudimg image runs NetAlertX 26.7.1 from the pinned upstream source tree, verified against its exact upstream commit at build time. It is tuned for Azure: virtual networks answer every ARP request with one synthetic hardware address, so the image ships the ICMP scanner with synthetic addressing enabled, which tracks each host on your virtual network as its own device rather than collapsing them all into one.
Secure by default: the image ships no working credential at all. Upstream ships its login switched off and, when enabled, uses a published default password; this image removes that default, binds the application interface to loopback so it cannot be reached directly, fronts the web interface with an authenticating reverse proxy, and generates a password unique to each VM on first boot into a root only file. Scanning is scoped to the VM's own subnet, resolved on first boot, so it never reaches beyond the network you deployed it into unless you widen it.
NetAlertX is GPL-3.0 licensed and free to use; the cloudimg charge covers packaging, security patching, image maintenance and 24/7 support. This image is provided by cloudimg and is not affiliated with or endorsed by the NetAlertX project.