Restart Network Service on AlmaLinux 9 and RHEL 9 – Easy Guide Steps

This tutorial will guide you through the process of restarting the network service on AlmaLinux 9 and RHEL 9. When you modify your Internet Protocol (IP) configuration, a restart of the network service is essential to implement those changes effectively.

You can easily restart the network service using various Linux commands. This guide will walk you through several methods to Restart Network Service on AlmaLinux 9 and RHEL 9, providing you with the knowledge to choose the best approach for your specific needs.

To successfully follow this guide, you will need access to your server as either a root user or a non-root user with sudo privileges. If you need assistance setting this up, refer to the Initial Server Setup guide on AlmaLinux 9.

Warning: Exercise caution when working with network services on remotely connected systems. Disabling the network service can lead to a loss of connection.

Step 1 – General ifconfig Command – Bring Network Interface up and down

A general method for managing network interfaces involves using the ifconfig command. This command allows you to bring a network interface up or down, effectively enabling or disabling it.

First, list your network interfaces on AlmaLinux 9 and RHEL 9 using the following command:

sudo ifconfig -a

This command will display all network interfaces, including those that are currently inactive. Identify the interface you wish to manipulate.

To turn off a specific network interface, use the following command, replacing <network-interface-name> with the actual name of the interface (e.g., eth0, enp0s3):

sudo ifdown <network-interface-name>

Similarly, to turn on a network interface, use the ifup command:

sudo ifup <network-interface-name>

Step 2 – Restart Network Service with NetworkManager on RHEL 9

NetworkManager is a dynamic network control and configuration system that attempts to keep network devices and connections active when they are available. It is commonly used on RHEL 9 and AlmaLinux 9. You can use the systemctl command to manage the NetworkManager service. To Restart Network Service on AlmaLinux 9 and RHEL 9, execute the following command:

sudo systemctl restart NetworkManager.service

This command will gracefully restart the NetworkManager service, applying any recent configuration changes.

Step 3 – Restart Network Services with nmcli Tool on RHEL 9

nmcli is a command-line tool for controlling NetworkManager. It provides a powerful and flexible way to manage network connections. To Restart Network Service on AlmaLinux 9 and RHEL 9 using nmcli, you can first disable networking and then re-enable it:

sudo nmcli networking off
sudo nmcli networking on

This sequence of commands effectively restarts the network service, forcing NetworkManager to re-establish all connections.

Conclusion

You have now learned how to use different Linux commands to turn off or turn on a network interface and Restart Network Service on AlmaLinux 9 and RHEL 9. Remember to be cautious when performing these actions on remote servers.

Hopefully, this guide was helpful. Feel free to leave comments or suggestions.

You might also find these articles useful:

• How To Configure Networking on AlmaLinux
• Test Network Throughput with Iperf Tool on Linux
• Monitor Linux Network Bandwidth Usage with nload Command

Alternative Solutions for Restarting the Network Service

While the methods outlined above are common and effective, here are two alternative approaches to Restart Network Service on AlmaLinux 9 and RHEL 9, along with explanations and code examples:

1. Using ip Command (More granular control):

The ip command is a powerful tool for managing network interfaces and routing. It provides more granular control compared to ifconfig and can be used to bring interfaces up or down, similar to the ifconfig approach, but with some advantages, especially in modern Linux distributions.

Explanation:

Instead of relying on the deprecated ifconfig or the broader NetworkManager, you can use the ip command to specifically target the interface you want to manipulate. This method is often preferred in scripting and automation because it offers more precise control and avoids potential conflicts with NetworkManager if you only want to modify a specific interface temporarily. The ip link set command modifies the state of the interface, bringing it up or down.

Code Example:

First, identify the interface name using:

ip link show

This command lists all network interfaces and their current status. Note the name of the interface you want to restart (e.g., eth0, enp0s3).

Then, to bring the interface down:

sudo ip link set dev <network-interface-name> down

Replace <network-interface-name> with the actual interface name.

Finally, to bring the interface back up:

sudo ip link set dev <network-interface-name> up

This approach avoids restarting the entire NetworkManager service, minimizing potential disruption to other network connections. It gives you precise control over a specific interface. After executing these commands, it is often necessary to reconfigure the IP address if it’s not statically assigned. For dynamically assigned addresses (DHCP), you can use the following after bringing the interface back up:

sudo dhclient <network-interface-name>

This command will request a new IP address from the DHCP server for the specified interface.

2. Using NetworkManager’s nmcli connection Command (Specific Connection Restart):

Instead of globally restarting the entire NetworkManager service or just turning networking off/on, you can restart a specific network connection managed by NetworkManager. This is particularly useful if you have multiple network connections defined (e.g., a wired connection and a wireless connection) and only want to refresh one of them.

Explanation:

NetworkManager manages network connections, each with its own profile and settings. Using nmcli connection down and nmcli connection up allows you to deactivate and reactivate a specific connection, effectively restarting it and forcing NetworkManager to re-establish the connection using the defined settings. This is a more targeted approach compared to restarting the entire NetworkManager service and less disruptive.

Code Example:

First, list the available network connections using:

nmcli connection show

This command will display a list of connection names (e.g., "Wired connection 1", "MyWifiNetwork"). Identify the connection you want to restart.

Then, to bring the connection down:

sudo nmcli connection down <connection-name>

Replace <connection-name> with the actual name of the connection.

Finally, to bring the connection back up:

sudo nmcli connection up <connection-name>

This method is generally preferred when you have specific connections configured in NetworkManager and you want to avoid affecting other connections by restarting the whole service. It offers a more targeted and less disruptive way to refresh a particular network connection’s configuration and state. Restart Network Service on AlmaLinux 9 and RHEL 9 can be done with this command.

These alternative methods provide flexibility and control over network management on AlmaLinux 9 and RHEL 9, allowing you to choose the most appropriate approach based on your specific requirements and the level of granularity you need.