Software & AppsOperating SystemLinux

How To Restart Dnsmasq

Ubuntu 14

Dnsmasq is a popular lightweight DNS forwarder and DHCP server. It’s commonly used in small networks and is the default DNS server in many Linux distributions. In this article, we will guide you on how to restart Dnsmasq in different scenarios.

Quick Answer

To restart Dnsmasq, you can either restart the NetworkManager service using the command "sudo systemctl restart network-manager.service" or use the command "sudo /etc/init.d/dnsmasq restart" for older versions of Linux. If you have multiple instances of Dnsmasq running, you can manually kill the process using the "pgrep dnsmasq" and "sudo kill <pid_of_dnsmasq>" commands, and then restart the NetworkManager service with "sudo service network-manager restart".

Understanding Dnsmasq

Before we delve into the process of restarting Dnsmasq, it’s crucial to understand what Dnsmasq is and what it does. Dnsmasq is a simple, lightweight, easy-to-configure DNS forwarder, designed to provide DNS (and optionally DHCP and TFTP) services to a small-scale network. It can serve the names of local machines which are not in the global DNS and provide round-robin DNS load balancing.

Restarting Dnsmasq

Restarting Dnsmasq can be accomplished in a variety of ways, depending on your system configuration. Here are the two most common methods:

1. Restart via NetworkManager

On most modern Linux distributions like Ubuntu 16.04 and newer versions, Dnsmasq is managed by a system and service manager called systemd. You can restart Dnsmasq by restarting the NetworkManager service. NetworkManager is a daemon that sits on top of libudev and other Linux kernel interfaces and manages network connections.

Command:

sudo systemctl restart network-manager.service

In this command, systemctl is a command to introspect and control the state of the systemd system and service manager. restart is an option to stop and then start a unit, in this case, the network-manager.service.

For older versions like Ubuntu 14.04.1 LTS, Debian 11, and Raspbian GNU/Linux 11, you can use the following command:

Command:

sudo /etc/init.d/dnsmasq restart

Here, /etc/init.d/ is a directory that contains scripts executed by init at startup and shutdown. dnsmasq is the script for the Dnsmasq service, and restart is the command to restart the service.

2. Restart via Killing the Process

If restarting NetworkManager doesn’t work or if you have multiple instances of Dnsmasq running, you can manually kill the process and then restart NetworkManager.

First, you need to find the process ID of the Dnsmasq instance you want to restart. You can do this using the pgrep dnsmasq command.

Command:

pgrep dnsmasq

pgrep is a command-line utility that searches the system’s active processes list for ones that match the regular expression given as an argument. In this case, it will return the process ID of the dnsmasq service.

Once you have the process ID, you can kill the process using the kill command followed by the process ID.

Command:

sudo kill <pid_of_dnsmasq>

Replace <pid_of_dnsmasq> with the process ID you found using the pgrep dnsmasq command.

Finally, restart the NetworkManager service.

Command:

sudo service network-manager restart

In this command, service is a command-line utility to start, stop and manage daemons/services, and network-manager is the service you want to restart.

Conclusion

Restarting Dnsmasq is a straightforward process once you understand how it works and how it’s managed on your system. Always ensure to choose the solution that matches your system configuration. If you encounter any issues, refer to the Dnsmasq documentation or seek help from online Linux communities.

What is Dnsmasq used for?

Dnsmasq is a lightweight DNS forwarder and DHCP server that is commonly used in small networks to provide DNS services and optionally DHCP and TFTP services. It can serve the names of local machines and provide round-robin DNS load balancing.

How do I restart Dnsmasq on Ubuntu 16.04 and newer versions?

On Ubuntu 16.04 and newer versions, Dnsmasq is managed by the NetworkManager service. You can restart Dnsmasq by restarting the NetworkManager service using the command sudo systemctl restart network-manager.service.

How do I restart Dnsmasq on Ubuntu 14.04.1 LTS, Debian 11, or Raspbian GNU/Linux 11?

On older versions like Ubuntu 14.04.1 LTS, Debian 11, and Raspbian GNU/Linux 11, you can restart Dnsmasq by using the command sudo /etc/init.d/dnsmasq restart.

What should I do if restarting NetworkManager doesn’t work or if multiple instances of Dnsmasq are running?

If restarting NetworkManager doesn’t work or if you have multiple instances of Dnsmasq running, you can manually kill the process and then restart NetworkManager. First, find the process ID of the Dnsmasq instance you want to restart using the command pgrep dnsmasq. Then, kill the process using the command sudo kill <pid_of_dnsmasq>. Finally, restart the NetworkManager service using the command sudo service network-manager restart.

Where can I find more information about Dnsmasq?

You can find more information about Dnsmasq in the official Dnsmasq documentation available at [http://www.thekelleys.org.uk/dnsmasq/doc.html]. Additionally, you can seek help from online Linux communities if you encounter any issues.

Leave a Comment

Your email address will not be published. Required fields are marked *