Namespace nodes: instant, image-free network endpoints
Not every node needs a container image or a VM disk. Namespace nodes are bare Linux network namespaces (a way to give a process its own private network) running directly on your computer's Linux. They have a full IP stack (addresses, routes, iptables/nftables firewall rules), start almost instantly, and need no image to pull, upload or manage.
Open Library → Namespace. No pull box, no upload area - just drag one from the device palette straight onto the canvas. Links wire in as veth pairs, hot-attachable even while the lab is running.
Namespace nodes are the cheapest thing on the canvas - use them for plain IP endpoints (a ping source, a route target) where you don't need a real userland. For anything that needs actual applications or a shell with installed tools, use Docker; for full vendor firmware, QEMU. See "What netplex. can run: the runtimes" for the full comparison.