nmtui Command Linux: Complete Guide to NetworkManager Text User Interface

The nmtui (NetworkManager Text User Interface) command is a powerful, menu-driven tool that provides an intuitive way to configure network connections in Linux systems. Unlike command-line tools that require memorizing complex syntax, nmtui offers a user-friendly text-based interface for managing NetworkManager settings, making network configuration accessible to both beginners and experienced administrators.

What is nmtui?

nmtui is part of the NetworkManager package and serves as a text-based user interface for configuring network connections. It’s particularly useful on servers without graphical interfaces or when you prefer working in the terminal. The tool provides a ncurses-based interface that allows you to navigate through menus using keyboard shortcuts.

Key Features of nmtui

• Interactive Menu System: Navigate through options using arrow keys
• Connection Management: Create, edit, and delete network connections
• Multiple Network Types: Support for Ethernet, WiFi, VPN, and more
• Real-time Status: View current network status and activate/deactivate connections
• No Root Required: Most operations can be performed by regular users

Installing nmtui

On most modern Linux distributions, nmtui comes pre-installed as part of the NetworkManager package. However, if it’s missing, you can install it using your distribution’s package manager:

Ubuntu/Debian

sudo apt update
sudo apt install network-manager

CentOS/RHEL/Fedora

# For CentOS/RHEL
sudo yum install NetworkManager-tui

# For Fedora
sudo dnf install NetworkManager-tui

Arch Linux

sudo pacman -S networkmanager

Basic nmtui Syntax and Usage

The basic syntax for nmtui is straightforward:

nmtui [OPTION]

Available Options

Navigating the nmtui Interface

When you launch nmtui, you’ll see a main menu with three primary options:

1. Edit a connection – Create, modify, or delete network connections
2. Activate a connection – Enable or disable existing connections
3. Set system hostname – Change the system’s hostname

Navigation Controls

• Arrow Keys: Navigate between menu items and fields
• Tab/Shift+Tab: Move between interface elements
• Enter: Select or activate an option
• Space: Toggle checkboxes or select items
• Esc: Go back or cancel current operation
• F10 or Ctrl+X: Exit nmtui

Managing Network Connections

Creating a New Ethernet Connection

To create a new wired Ethernet connection:

1. Launch nmtui: nmtui
2. Select “Edit a connection”
3. Choose “Add” and select “Ethernet”
4. Configure the connection parameters

Example Configuration

Profile name: Work-Ethernet
Device: eth0 (enp0s3)
□ Automatically connect
□ Available to all users

ETHERNET
Device: eth0 (enp0s3)
Cloned MAC address: _______________
MTU: _______ (automatic)

IPv4 CONFIGURATION 
Addresses: <Show>
DNS servers: _______________
Search domains: _______________
□ Require IPv4 addressing for this connection

IPv6 CONFIGURATION 
Addresses: <Show>
DNS servers: _______________
Search domains: _______________
□ Require IPv6 addressing for this connection

Configuring Static IP Address

To set up a static IP address instead of DHCP:

1. In the connection editor, change IPv4 Configuration from “Automatic” to “Manual”
2. Click “Show” next to Addresses
3. Add your static IP configuration

Static IP Example

IPv4 CONFIGURATION 
Addresses: 192.168.1.100/24
Gateway: 192.168.1.1
DNS servers: 8.8.8.8, 8.8.4.4
Search domains: example.com

Setting Up WiFi Connection

To configure a wireless connection:

1. Select “Edit a connection” from the main menu
2. Choose “Add” and select “Wi-Fi”
3. Enter the network details

WiFi Configuration Example

Profile name: Home-WiFi
Device: wlan0 (wlp2s0)
☑ Automatically connect
☑ Available to all users

WI-FI
SSID: MyHomeNetwork
Mode: Client
BSSID: _______________
Device: wlp2s0 (wlan0)
Cloned MAC address: _______________
MTU: _______ (automatic)

WI-FI SECURITY
Security: WPA & WPA2 Personal
Password: **************
☑ Show password

Activating and Deactivating Connections

The “Activate a connection” menu allows you to enable or disable network connections without editing their configuration.

Connection Status Display

Activate a connection

Ethernet
  Work-Ethernet         

Wi-Fi
  Home-WiFi            
  * Office-Guest        
  
VPN
  Company-VPN          

In this display:

• Active connections show a “Deactivate” button
• Inactive connections show an “Activate” button
• Asterisk (*) indicates the currently connected WiFi network

Advanced Configuration Options

VPN Configuration

nmtui supports various VPN types including OpenVPN, PPTP, and L2TP. To set up a VPN:

1. Go to “Edit a connection”
2. Select “Add” and choose your VPN type
3. Configure the VPN parameters

OpenVPN Example

Profile name: Company-VPN
☑ Automatically connect
☑ Available to all users

VPN
VPN type: OpenVPN
Gateway: vpn.company.com
☑ Set virtual device type
Device type: TUN
☑ Set virtual device name
Device name: tun0

Authentication:
Type: Certificates (TLS)
User Certificate: /path/to/client.crt
CA Certificate: /path/to/ca.crt
Private Key: /path/to/client.key

Bond and Bridge Connections

For advanced networking scenarios, nmtui supports creating bond and bridge connections:

Creating a Network Bond

Profile name: bond0
Device: bond0
☑ Automatically connect

BOND
Slaves: eth0, eth1
Mode: Active backup (active-backup)
Primary: eth0
Link monitoring: MII (recommended)
Monitoring frequency: 100

Hostname Configuration

The hostname setting feature allows you to change your system’s hostname directly from nmtui:

1. Select “Set system hostname” from the main menu
2. Enter the new hostname
3. Press OK to apply changes

Set Hostname

Hostname: mylinuxserver.local

                    <OK>     <Cancel>

Troubleshooting Common Issues

Permission Denied Errors

If you encounter permission issues, ensure your user is in the appropriate groups:

# Add user to network group
sudo usermod -a -G network $USER

# For some distributions, use netdev group
sudo usermod -a -G netdev $USER

NetworkManager Not Running

If nmtui fails to start, check if NetworkManager service is running:

# Check service status
systemctl status NetworkManager

# Start the service if stopped
sudo systemctl start NetworkManager

# Enable service to start on boot
sudo systemctl enable NetworkManager

Interface Not Appearing

If network interfaces don’t appear in nmtui:

1. Verify the interface exists: ip link show
2. Check if NetworkManager manages the interface: nmcli device status
3. Restart NetworkManager: sudo systemctl restart NetworkManager

nmtui vs Other Network Tools

Comparison with nmcli

When to Use nmtui

• Interactive configuration: When you need a guided interface
• Server administration: On headless servers without GUI
• Learning: Understanding NetworkManager concepts
• Quick changes: Making temporary network adjustments

Best Practices and Tips

Configuration Best Practices

1. Use descriptive names: Name connections clearly (e.g., “Office-WiFi”, “Home-Ethernet”)
2. Document settings: Keep notes of custom configurations
3. Test connections: Always verify connectivity after changes
4. Backup configurations: Save important network profiles

Security Considerations

• WiFi passwords: Use strong passwords for wireless networks
• VPN certificates: Secure VPN credential files properly
• User permissions: Limit network configuration access when necessary
• Connection availability: Consider whether connections should be “Available to all users”

Performance Optimization

# For high-performance networks, consider adjusting MTU
# Ethernet: Usually 1500 (default)
# Jumbo frames: 9000 (for supported networks)

# For WiFi, consider setting specific channels
# Use 'iwlist scan' to check available networks first

Integration with System Services

Systemd Integration

nmtui configurations integrate seamlessly with systemd services:

# View NetworkManager logs
journalctl -u NetworkManager

# Monitor network changes in real-time
journalctl -u NetworkManager -f

Firewall Considerations

When configuring networks through nmtui, remember that firewall rules may need adjustment:

# Check firewall status
sudo ufw status

# Allow connections on new network interfaces
sudo ufw allow in on eth1

Conclusion

The nmtui command provides an excellent balance between the simplicity of graphical network managers and the power of command-line tools. Its intuitive interface makes network configuration accessible while maintaining the flexibility needed for complex networking scenarios. Whether you’re managing a single desktop system or configuring servers in a data center, nmtui offers a reliable and user-friendly approach to NetworkManager configuration.

By mastering nmtui, you’ll be able to efficiently manage network connections, troubleshoot connectivity issues, and maintain robust network configurations across various Linux environments. The tool’s integration with NetworkManager ensures that your configurations are persistent and compatible with other network management utilities in the Linux ecosystem.