How to Restart Network on Ubuntu

Network connectivity issues can strike at the most inconvenient times, affecting productivity and causing frustration. Whether you’re experiencing connection drops, slow speeds, or configuration changes that need to be applied, knowing how to properly restart your network on Ubuntu is an essential skill for any Linux user. This comprehensive guide walks you through various methods to restart your network on Ubuntu systems, providing clear instructions for both beginners and experienced users alike.

Table of Contents

Introduction

Ubuntu, one of the most popular Linux distributions, offers several ways to manage network connections. Sometimes, when troubleshooting network issues or after making configuration changes, you may need to restart your network services to apply these changes or fix connection problems. Restarting your network can resolve issues like failed DNS resolution, IP address conflicts, or connectivity problems after system updates.

This guide covers network restart methods across different Ubuntu versions (18.04, 20.04, and 22.04), providing you with commands and procedures that work regardless of which version you’re running. By the end of this article, you’ll be equipped with multiple techniques to efficiently restart your network connection, tailored to different scenarios and system configurations.

Understanding Ubuntu’s Network Management System

Before diving into restart methods, it’s important to understand how Ubuntu manages network connections. This knowledge provides context for the commands and procedures we’ll explore later.

Ubuntu primarily uses NetworkManager for handling network connections across different interfaces. NetworkManager is a daemon that monitors and manages network connections, automatically configuring network devices and attempting to keep an active network connection available at all times.

Different network interfaces in Ubuntu include:

Ethernet: Typically named eth0, enp0s3, or similar
Wi-Fi: Usually named wlan0, wlp2s0, or similar
Virtual interfaces: Like VPN tunnels or bridges

Network configurations are stored in several locations:

/etc/NetworkManager/system-connections/: Contains connection profiles managed by NetworkManager
/etc/network/interfaces: Used for static interface configurations (though less common in modern Ubuntu installations)
/etc/netplan/: Used by the Netplan system on newer Ubuntu versions

The relationship between hardware and software components in Ubuntu networking is hierarchical. Physical devices (like network cards) are managed by kernel drivers, which expose interfaces that NetworkManager then controls. Understanding this structure helps troubleshoot network issues effectively.

Common Network Issues in Ubuntu

Several network problems can be resolved with a simple network restart. Recognizing these issues helps you determine when restarting is the appropriate solution.

Common symptoms indicating a network restart might be necessary include:

Inability to connect to websites despite active connection indicators
Extremely slow network speeds without apparent cause
Connection showing as “Limited” or “No Internet”
DNS resolution failures (can’t resolve domain names)
IP address conflicts or improper IP assignment
Network disconnections after waking from sleep or hibernation

Before restarting your network, run some basic diagnostic commands to identify the specific issue:

ip a                   # Shows network interfaces and their status
ping -c 4 8.8.8.8      # Tests basic internet connectivity
nslookup google.com    # Tests DNS resolution
route -n               # Shows the routing table

By identifying specific symptoms, you can better determine whether a network restart is likely to solve your problem or if more extensive troubleshooting is needed.

Preparing to Restart Your Network

Before restarting your network connection, take these important precautions:

Save any important work, especially if working on remote connections. A network restart will temporarily disconnect all network sessions.

Back up critical network configuration files:

sudo cp /etc/NetworkManager/NetworkManager.conf /etc/NetworkManager/NetworkManager.conf.backup
sudo cp /etc/netplan/*.yaml /etc/netplan/backup-$(date +%F).yaml

Check your current network status:

nmcli general status
nmcli connection show --active

Consider the impact on running services – applications relying on network connections might need to be restarted afterward.
Identify your network interfaces so you know which ones to restart:
```
ip link show
```

Taking these precautionary steps ensures you can recover quickly if anything goes wrong during the restart process.

Method 1: Using Network Manager Service Command

The simplest and most direct way to restart networking on Ubuntu is using the service command to restart the NetworkManager service.

Follow these detailed steps:

Open Terminal by pressing Ctrl+Alt+T
Enter the following command:
```
sudo service network-manager restart
```
Enter your password when prompted
Wait for the process to complete (usually takes 5-15 seconds)
Check the status of your network connection:
```
nmcli general status
```

This method is straightforward and works on most Ubuntu desktop installations. The network will temporarily disconnect during the restart process and then automatically reconnect to previously saved networks.

If you receive errors like “network-manager: unrecognized service,” it might indicate that your system is using a different network management method or that NetworkManager isn’t installed. In such cases, try the systemd method described next.

Method 2: Using Systemd Command

Modern Ubuntu versions use systemd for service management, making this method particularly reliable and recommended for Ubuntu 18.04 and newer.

To restart your network using systemd:

Open Terminal (Ctrl+Alt+T)

Enter the systemctl command:

sudo systemctl restart NetworkManager.service

Verify the service restarted properly:

sudo systemctl status NetworkManager.service

The output should show “Active: active (running)” with recent timestamp information.

The systemd method offers several advantages:

More detailed feedback about service status
Consistent behavior across different Ubuntu versions
Better handling of dependencies between services

If NetworkManager fails to restart properly, you might see error messages in the status output. Common issues include configuration errors or conflicts with other network management tools. Check logs for more details:

journalctl -u NetworkManager --since "10 minutes ago"

Method 3: Using nmcli Tool for Network Management

The NetworkManager Command Line Interface (nmcli) is a powerful tool that gives you fine-grained control over network connections. It’s particularly useful for servers or systems without a GUI.

To restart networking using nmcli:

Open Terminal (Ctrl+Alt+T)
Turn off networking completely:
```
sudo nmcli networking off
```
Wait a few seconds, then turn it back on:
```
sudo nmcli networking on
```
Verify the networking status:
```
nmcli general status
```

The nmcli tool provides extensive capabilities beyond simple restarts. You can use it to:

Restart specific connections only:

sudo nmcli connection down "connection-name"
sudo nmcli connection up "connection-name"

Check available connections:
```
nmcli connection show
```
Get detailed information about a specific connection:
```
nmcli connection show "connection-name"
```

This method gives you precise control over your network environment and is especially useful when you need to restart only specific connections while leaving others intact.

Method 4: Using ifup & ifdown Commands

The ifup and ifdown commands are traditional network management tools that work with interfaces defined in the /etc/network/interfaces file. While less common in modern Ubuntu desktop installations, they’re still useful for systems configured with static networking.

First, ensure you have the required package installed:

sudo apt install ifupdown

To restart your network interface:

Identify your network interface name:
```
ip a
```
Note the interface name (e.g., eth0, enp0s3, wlan0)
Bring the interface down:
```
sudo ifdown interface-name
```
For example: sudo ifdown enp0s3
Bring the interface back up:
```
sudo ifup interface-name
```
To restart all interfaces at once:
```
sudo ifdown -a
sudo ifup -a
```

This method is particularly useful for:

Server environments with static IP configurations
Systems not using NetworkManager
Legacy Ubuntu configurations

Be cautious when using this method remotely, as bringing down the interface you’re connected through will terminate your session. Always have an alternative access method available when working remotely.

Method 5: Graphical Approach for Desktop Users

Ubuntu desktop users can take advantage of the graphical interface to restart network connections without using terminal commands.

To restart networking using the GUI:

Click on the network icon in the top-right corner of your screen (in the system tray)
Select the active network connection you want to restart
Click on “Turn Off” to disable the connection
After the connection is disabled, click on the network icon again
Select “Connect” to re-enable the network connection

The specific steps might vary slightly depending on your Ubuntu version and desktop environment (GNOME, KDE, etc.), but the general process remains similar.

This method is recommended for:

Users uncomfortable with command-line operations
Quick network toggles without opening terminal
Confirming that network issues aren’t related to hardware switches

If the network icon doesn’t appear in your system tray, you might need to check if the network-manager-gnome (or equivalent) package is installed:

sudo apt install network-manager-gnome

Method 6: Using nmtui for Terminal-Based UI Management

For users who prefer a text-based user interface over command-line commands, NetworkManager Text User Interface (nmtui) provides a menu-driven approach to network management.

To use nmtui:

Install it if not already present:
```
sudo apt install network-manager
```
Launch the text-based interface:
```
sudo nmtui
```
Navigate using arrow keys, Tab, and Enter
Select “Activate a connection”
Choose the connection you want to restart
First, deactivate it by selecting it and pressing Enter
Then, activate it again by selecting it and pressing Enter

The nmtui tool is particularly beneficial for:

Server administrators managing systems remotely
Users who prefer menu-driven interfaces
Environments where graphical interfaces aren’t available
Systems accessed via SSH or console connections

This user-friendly approach combines the power of command-line tools with the intuitive navigation of a graphical interface, making it an excellent middle ground for many administrators.

Restarting Specific Network Components

Sometimes you don’t need to restart the entire network system but just specific components or connection types.

Restarting Wi-Fi Only

To restart just your wireless connection:

sudo nmcli radio wifi off
sudo nmcli radio wifi on

Or for a specific wireless connection:

sudo nmcli connection down "WiFi-Connection-Name"
sudo nmcli connection up "WiFi-Connection-Name"

Restarting Ethernet Only

For wired connections:

# Using ip command
sudo ip link set eth0 down
sudo ip link set eth0 up

# Or using nmcli (replace "Wired connection 1" with your connection name)
sudo nmcli connection down "Wired connection 1"
sudo nmcli connection up "Wired connection 1"

Managing VPN Connections

VPN connections can be restarted independently:

# List VPN connections
nmcli connection show | grep vpn

# Restart a specific VPN
sudo nmcli connection down "VPN-Name"
sudo nmcli connection up "VPN-Name"

These targeted approaches help minimize disruption to other services while addressing specific network component issues.

Automating Network Restarts

For recurring network issues or scheduled maintenance, automating network restarts can be useful.

Creating a Simple Bash Script

Create a file named restart-network.sh:

#!/bin/bash
# Network restart script

echo "Restarting network..."
sudo systemctl restart NetworkManager.service

# Check if restart was successful
if [ $? -eq 0 ]; then
    echo "Network restarted successfully"
    # Log successful restart
    echo "$(date): Network restart successful" >> /var/log/network-restarts.log
else
    echo "Network restart failed"
    # Log failed restart
    echo "$(date): Network restart failed" >> /var/log/network-restarts.log
fi

Make it executable:

chmod +x restart-network.sh

Scheduling with Cron

To schedule automatic network restarts (for example, every day at 3 AM):

crontab -e

Add this line:

0 3 * * * /path/to/restart-network.sh

For security reasons, consider these automation best practices:

Use script logging to track restart events
Implement error handling in scripts
Avoid scheduling restarts during critical operations
Use proper permissions to prevent unauthorized script execution

Troubleshooting Failed Network Restarts

Sometimes network restarts don’t resolve issues or even create new problems. Here’s how to diagnose and fix common failures.

Common Error Messages and Solutions

“Connection activation failed”
- Check if any configurations have changed
- Verify that the physical connection is working
- Test with sudo ip link set interface-name up
“NetworkManager is not running”
- Restart NetworkManager: sudo systemctl start NetworkManager
- If it fails to start, check logs: journalctl -u NetworkManager
“Device not managed by NetworkManager”
- Check /etc/NetworkManager/NetworkManager.conf for [ifupdown] section
- Ensure the device isn’t marked as unmanaged

Using Logs for Diagnosis

When troubleshooting network issues, logs provide crucial information:

# NetworkManager logs
journalctl -u NetworkManager --since "10 minutes ago"

# System logs related to networking
dmesg | grep -i net

# DHCP client logs
journalctl | grep -i dhcp

Look for patterns of errors or warnings that might indicate underlying issues like hardware problems, driver issues, or configuration conflicts.

Advanced Network Restart Scenarios

Beyond basic network restarts, advanced users might need to handle specialized environments.

Containerized Environments

When running Ubuntu within containers like Docker or LXC:

Network namespace separation means container networking is partially isolated
Restart container’s network from host: lxc-attach -n container-name -- systemctl restart NetworkManager
For Docker: docker exec container-name systemctl restart NetworkManager

Virtualized Ubuntu Instances

For Ubuntu running as a virtual machine:

VM network adapters might need special consideration
Some hypervisors require specific drivers
Check hypervisor-specific network settings if restart doesn’t resolve issues

Enterprise Network Configurations

In enterprise settings with complex networking:

Consider the impact on bonded interfaces and redundant connections
Plan for potential service disruptions during restarts
Test restart procedures during maintenance windows
Document network configurations for faster troubleshooting

Monitoring Network Status After Restart

After restarting your network, verify everything is functioning correctly:

Check assigned IP address:
```
ip address show
```
Ensure you received a proper IP address from DHCP or that your static IP is correctly applied.
Verify DNS resolution:
```
nslookup google.com
```
Successful resolution confirms DNS is working properly.
Test local network connectivity:
```
ping -c 4 $(ip route | grep default | awk '{print $3}')
```
This pings your default gateway to verify local network connectivity.
Test internet connectivity:
```
ping -c 4 8.8.8.8
```
Success indicates internet routing is working.

For continuous monitoring, tools like iftop, nethogs, or vnstat can help track network performance and identify potential issues before they cause major problems.

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