dig is a great tool for looking up DNS (domain name server) issues on your web server, or between servers, via SSH (secure shell). When using it on the CentOS server, you receive an error as below.
[root@server1 ~]# dig
-bash: dig: command not found
Some control panel providers consider it a security risk & they uninstall it when control panel is being installed. You can simply install it using yum by logging into the server via SSH.
[root@server1 ~]# yum install bind-utils
Helps in troubleshooting DNS issues which you face from the server.