FreeBSD Jails + VNET: Your Private Cloud Without Docker

🔐 FreeBSD Jails + VNET: Build Your Own Private Cloud in One Machine (No Docker Needed)

“Docker is a container illusion. FreeBSD Jails are kernel reality.” — LuxBSD

🧠 Imagine This

You’re running 5 isolated servers:

Each with its own IP address
Each with a real firewall
Each with a dedicated network stack
Each booting in milliseconds
All using zero hypervisors or Docker layers

And it’s all happening inside a single FreeBSD installation — using only native tools.

💡 What You’ll Build

⚡ Jails for process-level isolation
🌐 VNET for full virtual networking
🔥 PF firewall rules per jail
🧱 Multiple IPs on loopback or bridges
🛰️ External-facing services (nginx, ssh, PostgreSQL, etc.)
🕵️‍♂️ Optional traffic monitoring per jail

🛠️ Why Is This Better Than Docker?

Feature	Docker	FreeBSD Jails + VNET
True kernel isolation	❌ userspace only	✅ native process jail
Full network stack per container	❌ hacky	✅ real VNET
Resource efficiency	⚠️ moderate	✅ extremely high
Boot time	⚠️ seconds	✅ sub-second
Security	⚠️ patchwork	✅ built-in
Stability	⚠️ variable	✅ rock-solid
System overhead	❌ daemon required	✅ kernel-native

🧪 What You’ll Learn

Create custom bridges and virtual NICs
Bind jails to specific IPs
Route traffic with pf.conf
Manage jail templates with ezjail or bastille
Secure and isolate traffic per jail

🔧 Quick Preview of Setup

1. Create bridge and epair interface

ifconfig bridge0 create
ifconfig epair0 create
ifconfig bridge0 addm epair0a up
ifconfig epair0b up

2. Configure IP for jail

sysrc cloned_interfaces="epair0b"
sysrc ifconfig_epair0b="inet 10.0.0.10/24"
sysrc defaultrouter="10.0.0.1"

3. Jail configuration file (/etc/jail.conf)

myjail {
    host.hostname = "jail1.local";
    path = "/usr/jails/myjail";
    mount.devfs;
    persist;
    vnet;
    vnet.interface = "epair0b";
    exec.start = "/bin/sh /etc/rc";
    exec.stop = "/bin/sh /etc/rc.shutdown";
}

4. Start the jail

service jail start myjail

🔒 PF Firewall Example

/etc/pf.conf:

ext_if="em0"
jail_if="bridge0"

table <jails> persist { 10.0.0.10, 10.0.0.11 }

block in all
pass out all keep state

pass in on $ext_if inet proto tcp from any to <jails> port { 80 443 } keep state

pfctl -f /etc/pf.conf
pfctl -e

🌌 Why You’ll Fall in Love

This is how Netflix scaled traffic worldwide. How CTF players build hardened labs. How you can simulate an entire datacenter — on your laptop.

⚔️ Conclusion

“If you install FreeBSD only to experience this — you won’t regret it. Build your own secure, modular, ultra-fast private cloud. Then laugh at everything else.”