What is dnsmasq in CentOS?

dnsmasq is a very lightweight and simple DNS server. dnsmasq can be configured to be a DNS server and a DHCP server. In this article, I am going to show you how to configure dnsmasq DNS server on CentOS 7. I am also going to talk about some of the common DNS server configuration options of dnsmasq.

How configure dnsmasq conf?

The dnsmasq server can be configured via the /etc/dnsmasq. conf file (which contains well commented and explained options), and user-defined configuration files can also be added in the /etc/dnsmasq. d directory. DNS is enabled by default, so before making any changes, make sure to create a backup of /etc/dnsmasq.

How use dnsmasq Linux?

Specify different or extra options to DHCP clients. By default, dnsmasq sends some standard options to DHCP clients, the netmask and broadcast address are set to the same as the host running dnsmasq, and the DNS server and default route are set to the address of the machine running dnsmasq.

How do I know if dnsmasq is working?

Dnsmasq troubleshooting

  1. See if dnsmasq is running with ps guax | grep dnsmasq.
  2. Check the dnsmasq configuration files in /etc/dnsmasq.d.
  3. There should be some settings in them and they should not mentioned that a service (DNS or DHCP) is not enabled.

How do I fix dnsmasq?

Each host in your test will need to have its DNS settings updated to point to the new DNS server.

  1. 1 – Update /etc/resolv. conf to add new name server.
  2. 2 – Prevent overwriting of /etc/resolv. conf.
  3. 3 – Test the new name server. Use nslookup to test name/ip resolution for entries in your DNS tables.

What is dnsmasq vulnerability?

Over the years, multiple critical vulnerabilities have been found in dnsmasq. Recently, security researchers discovered new issues that continue to make dnsmasq vulnerable. These vulnerabilities can lead to DNS cache poisoning, denial of service (DoS) and possibly remote code execution (RCE).