Docker Networking Tutorial: Build Container Networks From Scratch (Linux Namespaces)

How do containers get their own IP address without a virtual machine? In this video, we break down Linux Network Namespaces and show how container networking actually works under the hood. Instead of relying on Docker or Kubernetes abstractions, we build everything from scratch using ip netns and unshare the exact primitives used by the Linux kernel. You’ll see how a normal Linux system connects to the network, how routing works, and how we can isolate processes into completely separate network stacks. What you'll learn: • How Linux networking works (ip addr, ip route, default gateway) • Why containers have their own IP addresses • How to create isolated network namespaces using ip netns • How to simulate real container environments using unshare --net • How containers use namespaces at the process level ⚙️ Commands covered: ip addr · ip route · ip netns add · ip netns exec · ip link set lo up · unshare --net · ping · ip netns delete If you're learning DevOps, Docker, Kubernetes, or Linux internals, this is a must-watch. ▬▬▬▬▬▬▬ Timestamps ▬▬▬▬▬▬▬ 00:00 - Intro 00:21 - What Normal Networking Looks Like on a Linux Host (ip addr & ip route) 01:30 - How a Linux Process Reaches the Outside World (Default Route & Gateway) 02:28 - Creating Isolated Network Stacks with ip netns (Step-by-Step) 08:55 - Simulating Real Container Networking with unshare --net 10:08 - Cleaning Up: Deleting Network Namespaces the Right Way 10:46 - Outro & What's Next in Kernel Primitives Watch Related Playlists: - Kubernetes Gateway API: https://www.youtube.com/playlist?list=PL-K2rw28HIwYxzgTFmObuFhfctfBPAc6h - Kubernetes: https://www.youtube.com/playlist?list=PL-K2rw28HIwZVMo9CtbV0wDu548SN0h9Y - Github Actions: https://www.youtube.com/playlist?list=PL-K2rw28HIwYfq7SqYnBzAxlUhcYP7ldM - Ansible: https://www.youtube.com/playlist?list=PL-K2rw28HIwaavCXTYEWF4mP431KmKtEY - AWX: https://www.youtube.com/playlist?list=PL-K2rw28HIwbTtijpBMrOaHdnWGXdOkYa - AI: https://www.youtube.com/playlist?list=PL-K2rw28HIwaSvmI8oFeSQDl4cVTdxaGQ ▬▬▬▬▬▬ Connect with me ▬▬▬▬▬▬ LinkedIn: https://www.linkedin.com/in/kumar-nikhil811/ Website: https://techinik.com Medium: https://medium.com/@kumarnikhil811 #linux #containers #devops #docker #kubernetes #networking