you can stop iptables, but Docker will not work correctly without it — at least not for networking.

🔥 Here’s what will break if you stop iptables:

Feature Effect of stopping iptables
🐳 Container-to-container communication ❌ Likely to break
🌍 Port publishing (-p 8080:80) ❌ Will no longer be routed to container
🛡️ NAT/bridge networking ❌ Broken (DNAT/SNAT won’t happen)
🧱 Docker bridge isolation ❌ Broken (containers may become reachable in unsafe ways)
📡 Host to container via mapped ports ❌ Will stop working unless you’re using --network=host

⚠️ Why Docker Needs iptables

Docker uses iptables rules to:

  • Handle NAT (e.g., PREROUTING for -p 80:80)
  • Control bridge traffic (for docker0 and user-defined bridges)
  • Enforce isolation between containers and the outside world

These rules are automatically created by the Docker daemon unless you explicitly disable them (which is not recommended unless you manage them manually).

✅ Safe Alternatives

If you’re debugging or trying to isolate an issue:

  • Flush only the nat or filter chains:

    sudo iptables -t nat -F
sudo iptables -F

  • Restart Docker afterward to repopulate rules:

    sudo systemctl restart docker

❌ Don’t do this (unless in testing/sandbox):

sudo systemctl stop iptables

This will kill all firewall rules including the ones Docker relies on for:

  • Port forwarding (-p)
  • NAT translation
  • Bridge routing

Conclusion: Stopping iptables is not recommended unless you’re running Docker in --network=host mode or in a restricted custom environment (e.g. Kubernetes CNI plugin with its own rules). Instead, clear or adjust specific chains if needed, and let Docker manage the rules automatically.