Chapter 10. Troubleshooting DNS Services

As the Domain Name System (DNS) is probably the most influential technology in the world of IT, at some point in your career you should expect that it will be presented to you as an ongoing issue that needs to be managed and resolved. DNS servers come in various forms, and your level of control may vary depending on the type of infrastructure you have access to but, regardless of this, the issues will undoubtedly remain the same, in whole or part.

Having already reviewed the virtue of dig and the various other networking tools, in the final few pages of this book we will now discuss the process of troubleshooting CentOS 7 with specific regard to monitoring issues related to DNS as a function of the overall system health check.

In this chapter, we will:

• Learn how to change the hostname of the system using hostnamectl and managing the fqdn with /etc/hosts

• Learn how to perform a few basic system and BIND-based sanity checks before hitting the panic button...