NetBox Enterprise Requirements for Ubuntu

Overview

This guide provides Ubuntu-specific preparation steps for NetBox Enterprise Embedded Cluster installation. Complete these steps before running the NetBox Enterprise installer.

Prerequisites:

• Review general NetBox Enterprise requirements
• Fresh Ubuntu 22.04 LTS or 24.04 LTS installation
• Root or sudo access
• Static IP address configured

Tested Versions

NetBox Enterprise has been tested on the following Ubuntu LTS releases:

Version	Release Name	Kernel	Support Status
Ubuntu 24.04 LTS	Noble Numbat	6.8+	Recommended
Ubuntu 22.04 LTS	Jammy Jellyfish	5.15+	Supported

Note: While Ubuntu meets kernel 4.3+ requirements, LTS versions receive extended support and are recommended for production deployments.

Firewall Configuration Options

Ubuntu supports two firewall management approaches. Choose ONE method based on your environment:

Approach	When to Use	Advantages	Disadvantages
Direct iptables	Default Ubuntu installations, headless servers	Simple, direct control, fewer dependencies	Manual rule management, no built-in CLI
UFW (Uncomplicated Firewall)	Desktop installations, existing UFW deployments	User-friendly commands, preset application profiles	Additional abstraction layer

Important: Choose One Method

Using both iptables and UFW simultaneously can cause conflicts. Select the method that matches your environment and stick with it.

Preparation Steps

Step 1: Disable Swap

Kubernetes requires swap to be disabled to ensure predictable memory allocation.

sudo swapoff -a
sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

# Verify: should return no output
swapon --show

Step 2: Configure Firewall Rules

Choose ONE firewall configuration method:

Option A: Direct iptables (Recommended for Servers)

Install iptables-persistent to save rules across reboots:

sudo apt update && sudo apt install -y iptables-persistent

Configure pod networking for Kubernetes:

# Allow pod-to-pod communication across Kubernetes networks
sudo iptables -I FORWARD -s 10.244.0.0/17 -d 10.244.128.0/17 -j ACCEPT
sudo iptables -I OUTPUT -s 10.244.0.0/17 -d 10.244.128.0/17 -j ACCEPT
sudo iptables -I FORWARD -s 10.244.128.0/17 -d 10.244.0.0/17 -j ACCEPT
sudo iptables -I OUTPUT -s 10.244.128.0/17 -d 10.244.0.0/17 -j ACCEPT

# Save rules persistently
sudo netfilter-persistent save

# Verify rules are configured
sudo iptables -L FORWARD -n | grep 10.244

Option B: UFW (For Existing UFW Environments)

Install and enable UFW:

sudo apt install -y ufw
sudo ufw --force enable

Open required Kubernetes and NetBox Enterprise ports:

# Kubernetes API and control plane
sudo ufw allow 6443/tcp
sudo ufw allow 2379:2380/tcp
sudo ufw allow 10250,10251,10252,10255,5473,10257,10259/tcp

# NodePort services range
sudo ufw allow 30000:32767/tcp

# Pod networking (VXLAN and BGP)
sudo ufw allow 4789/udp
sudo ufw allow 179/tcp

Configure pod networking through UFW:

# Route rules for pod-to-pod communication
sudo ufw route allow from 10.244.0.0/17 to 10.244.128.0/17
sudo ufw route allow from 10.244.128.0/17 to 10.244.0.0/17

# Reload firewall
sudo ufw reload

# Verify routing rules
sudo ufw status | grep 10.244

Step 3: Load Kernel Modules

Load and persist required kernel modules for container networking:

# Load modules immediately
sudo modprobe br_netfilter ip_vs ip_vs_rr ip_vs_wrr ip_vs_sh overlay

# Configure modules to load on boot
cat <<EOF | sudo tee /etc/modules-load.d/kubernetes.conf
br_netfilter
ip_vs
ip_vs_rr
ip_vs_wrr
ip_vs_sh
overlay
EOF

# Apply system configuration
sudo sysctl --system

# Verify modules are loaded
lsmod | grep -E 'br_netfilter|ip_vs|overlay'

Step 4: Reboot and Verify

Reboot to apply all system changes:

sudo reboot now

Post-Reboot Verification:

swapon --show                              # Should return nothing
lsmod | grep -E 'br_netfilter|ip_vs|overlay'
sudo iptables -L -n | grep 10.244          # Or: sudo ufw status | grep 10.244

Pre-Installation Checklist

Before proceeding to installation, verify all requirements:

• Ubuntu 22.04 LTS or 24.04 LTS installed
• Swap memory disabled and verified
• Firewall configured (iptables OR UFW, not both)
• Pod networking rules configured (10.244.0.0/17 ↔ 10.244.128.0/17)
• Kernel modules loaded (br_netfilter, ip_vs, overlay)
• System rebooted and changes verified
• Static IP address configured
• Hostname is resolvable

Next Steps

1. Proceed to Installation: Follow the NetBox Enterprise installation guide
2. Review Special Configurations: If using proxies, SELinux, or restricted environments, see special configurations
3. Plan Data Migration (Optional): Review the migration guide if importing existing NetBox data

Troubleshooting

Firewall Issues

Problem: Cannot connect to admin console or NetBox after installation

Solution:

Verify firewall allows required ports:

# For iptables
sudo iptables -L -n | grep -E '6443|30000|443|80'

# For UFW
sudo ufw status | grep -E '6443|30000|443|80'

If ports are missing, add them manually:

# iptables
sudo iptables -I INPUT -p tcp --dport 30000 -j ACCEPT
sudo netfilter-persistent save

# UFW
sudo ufw allow 30000/tcp
sudo ufw allow 443/tcp
sudo ufw allow 80/tcp

Pod Networking Issues

Problem: Pods cannot communicate with each other

Solution:

Verify pod networking rules:

# iptables
sudo iptables -L FORWARD -n | grep 10.244

# UFW
sudo ufw status | grep 10.244

If rules are missing, reconfigure pod networking following Step 2 above.

Kernel Module Issues

Problem: Installation fails with kernel module errors

Solution:

Manually verify and reload modules:

# Check if modules exist
modinfo br_netfilter
modinfo overlay

# Reload modules
sudo modprobe br_netfilter ip_vs ip_vs_rr ip_vs_wrr ip_vs_sh overlay

# Verify loaded
lsmod | grep -E 'br_netfilter|ip_vs|overlay'

If modules don't exist, install kernel headers:

sudo apt update
sudo apt install -y linux-headers-$(uname -r)

See also: General requirements, Linux changes, Troubleshooting