nmtui - NetworkManager Text User Interface

1. Introduction to nmtui

1.1 What is nmtui?

nmtui (NetworkManager Text User Interface) is a curses-based terminal interface for NetworkManager. It provides a user-friendly, menu-driven alternative to the command-line nmcli tool, making network configuration accessible without memorizing commands or flags.

1.2 When to Use nmtui vs nmcli

1.3 Installation and Requirements

# Usually pre-installed on systems with NetworkManager
# If not installed:

# Debian/Ubuntu
sudo apt-get install network-manager

# RHEL/CentOS/Fedora
sudo yum install NetworkManager-tui
# or
sudo dnf install NetworkManager-tui

# Arch Linux
sudo pacman -S networkmanager

# Verify installation
which nmtui
nmtui --version

2. Launching nmtui

2.1 Basic Launch

# Launch main menu
nmtui

# Direct access to specific functions
nmtui edit          # Go directly to Edit a connection
nmtui connect       # Go directly to Activate a connection
nmtui hostname      # Go directly to Set system hostname

2.2 Navigation Basics

3. Main Menu Overview

    ┌───────────────────────────────────────┐
    │                                       │
    │   Edit a connection                   │
    │   Activate a connection               │
    │   Set system hostname                 │
    │                                       │
    │   <Quit>                              │
    │                                       │
    └───────────────────────────────────────┘
            

3.1 Main Menu Options

4. Editing Connections

4.1 Connection List Screen

    ┌─────────────────────────────────────────────┐
    │ Connection: Wired connection 1              │
    │             Home WiFi                       │
    │             Office VPN                      │
    │                                             │
    │ <Add>  <Edit...>  <Delete>  <Back>         │
    └─────────────────────────────────────────────┘
            

4.2 Adding a New Connection

4.3 Connection Types

4.4 Ethernet Connection Configuration

    ┌────────────────────────────────────────────┐
    │ Profile name: My-Ethernet_____________     │
    │ Device: eth0___________________________    │
    │                                            │
    │ ═ ETHERNET                                 │
    │   Cloned MAC address: __________________   │
    │   MTU: __________                          │
    │                                            │
    │ ═ IPv4 CONFIGURATION  <Automatic>  ▼      │
    │   Addresses: 192.168.1.100/24________      │
    │   Gateway: 192.168.1.1_______________      │
    │   DNS servers: 8.8.8.8_______________      │
    │   Search domains: ___________________      │
    │                                            │
    │ ☐ Require IPv4 addressing                  │
    │                                            │
    │ ═ IPv6 CONFIGURATION  <Automatic>  ▼      │
    │                                            │
    │ ☑ Automatically connect                    │
    │ ☐ Available to all users                   │
    │                                            │
    │         <Cancel>        <OK>               │
    └────────────────────────────────────────────┘
            

Key Fields Explained

4.5 IPv4 Configuration Modes

    IPv4 CONFIGURATION  <Manual>  ▼
                        ├ Disabled
                        ├ Automatic (DHCP)
                        ├ Manual (Static IP)
                        ├ Link-Local
                        └ Shared
            

4.6 Configuring Static IP Address

4.7 WiFi Connection Configuration

    ┌────────────────────────────────────────────┐
    │ Profile name: Home-WiFi________________    │
    │ Device: wlan0__________________________    │
    │                                            │
    │ ═ WI-FI                                    │
    │   SSID: MyNetwork__________________        │
    │   Mode: <Client> ▼                         │
    │   BSSID: __________________________        │
    │                                            │
    │ ═ WI-FI SECURITY                           │
    │   Security: <WPA & WPA2 Personal> ▼        │
    │   Password: ************************       │
    │   ☐ Show password                          │
    │                                            │
    │ ═ IPv4 CONFIGURATION  <Automatic>  ▼      │
    │                                            │
    │ ☑ Automatically connect                    │
    │                                            │
    │         <Cancel>        <OK>               │
    └────────────────────────────────────────────┘
            

WiFi Security Types

4.8 Additional Connection Options

Checkboxes at Bottom of Edit Screen

4.9 Editing Existing Connections

4.10 Deleting Connections

5. Activating Connections

5.1 Activate a Connection Screen

    ┌────────────────────────────────────────────┐
    │ Ethernet                                   │
    │   ● Wired connection 1                     │
    │     Office-Static                          │
    │                                            │
    │ Wi-Fi                                      │
    │   ● Home-WiFi                              │
    │     CoffeeShop-Guest                       │
    │     OfficeNetwork                          │
    │                                            │
    │ VPN                                        │
    │     Corporate-VPN                          │
    │                                            │
    │                <Back>                       │
    └────────────────────────────────────────────┘
    
    ● = Active connection
            

5.2 Activating/Deactivating Connections

5.3 Connection Status Indicators

6. Setting System Hostname

6.1 Hostname Configuration Screen

    ┌────────────────────────────────────────────┐
    │ Set system hostname                        │
    │                                            │
    │ Hostname: myserver____________________     │
    │                                            │
    │                                            │
    │         <Cancel>        <OK>               │
    └────────────────────────────────────────────┘
            

6.2 Changing Hostname

6.3 Verifying Hostname Change

# Check current hostname
hostname

# Check all hostname info
hostnamectl status

# Alternative check
cat /etc/hostname

7. Common Configuration Scenarios

7.1 Scenario: Home DHCP Connection

7.2 Scenario: Static IP Server

7.3 Scenario: WiFi with Hidden SSID

7.4 Scenario: Secondary IP Address

7.5 Scenario: Connection Priority

8. Troubleshooting in nmtui

8.1 Connection Won't Activate

8.2 Can't See Network Device

8.3 Changes Not Saving

8.4 nmtui Performance Issues

9. Best Practices

9.1 Connection Naming

9.2 Configuration Guidelines

9.3 Security Best Practices

9.4 Documentation Habits

10. nmtui vs nmcli Quick Reference

10.1 Task Comparison

10.2 When to Choose Which Tool

11. Advanced Tips and Tricks

11.1 Keyboard Shortcuts

11.2 Quick Launch Scripts

#!/bin/bash
# Quick network configuration launcher

# Add to ~/.bashrc or ~/.bash_aliases
alias netedit='sudo nmtui edit'
alias netconn='sudo nmtui connect'
alias nethost='sudo nmtui hostname'

# Or create a wrapper
network-config() {
    case "$1" in
        edit|e)
            sudo nmtui edit
            ;;
        connect|c)
            sudo nmtui connect
            ;;
        hostname|h)
            sudo nmtui hostname
            ;;
        *)
            sudo nmtui
            ;;
    esac
}

# Usage:
# network-config edit
# network-config connect
# network-config hostname

11.3 Terminal Optimization

11.4 Backup and Restore

# Backup all NetworkManager connections
sudo tar -czf nm-backup-$(date +%Y%m%d).tar.gz \
    /etc/NetworkManager/system-connections/

# Restore connections
sudo tar -xzf nm-backup-20241025.tar.gz -C /

# Fix permissions
sudo chmod 600 /etc/NetworkManager/system-connections/*
sudo chown root:root /etc/NetworkManager/system-connections/*

# Reload in nmtui
# Just restart nmtui - it will detect changes automatically

# Or reload via command line
sudo nmcli connection reload

12. Integration with System Administration

12.1 Using nmtui in Installation Scripts

#!/bin/bash
# Post-installation network setup

# Check if NetworkManager is running
systemctl start NetworkManager
systemctl enable NetworkManager

# Launch nmtui for user configuration
echo "Please configure network settings..."
nmtui

# Verify connectivity
if ping -c 3 8.8.8.8 &>/dev/null; then
    echo "Network configured successfully"
else
    echo "Network configuration may need adjustment"
fi

12.2 Monitoring Changes

# Watch for connection file changes
inotifywait -m /etc/NetworkManager/system-connections/ -e modify -e create -e delete |
while read path action file; do
    echo "$(date): Connection $file was $action"
done

# Log nmtui usage (for auditing)
alias nmtui='logger "nmtui launched by $USER" && /usr/bin/nmtui'

13. Troubleshooting Connection Issues

13.1 Diagnostic Checklist

13.2 Common Error Messages

14. Reference: Configuration Files

14.1 Where nmtui Stores Settings

# Connection profiles (created/edited by nmtui)
/etc/NetworkManager/system-connections/

# Example connection file
/etc/NetworkManager/system-connections/Wired-connection-1.nmconnection

# NetworkManager main config
/etc/NetworkManager/NetworkManager.conf

# Check current hostname
/etc/hostname

# View connection file
sudo cat /etc/NetworkManager/system-connections/My-Connection.nmconnection

14.2 Connection File Format

[connection]
id=My-Ethernet
uuid=12345678-1234-1234-1234-123456789abc
type=ethernet
autoconnect=true
permissions=

[ethernet]
mac-address-blacklist=

[ipv4]
address1=192.168.1.100/24,192.168.1.1
dns=8.8.8.8;8.8.4.4;
dns-search=
method=manual

[ipv6]
addr-gen-mode=stable-privacy
dns-search=
method=auto

[proxy]

15. Summary and Quick Start

Essential Keyboard Commands

• ↑ ↓ - Navigate menu items
• Tab - Move between fields
• Enter - Select/activate
• Space - Toggle checkboxes
• Esc - Go back/cancel
• F10 - Exit nmtui

Remember

• nmtui is for interactive configuration
• Use nmcli for scripts and automation
• Changes are saved to /etc/NetworkManager/system-connections/
• Most changes require connection reactivation
• Always verify connectivity after changes
• Backup connection files before major changes