Here’s how to troubleshoot nameservers with dig.

<pre lang="bash">
dig hostname
dig domain.com

To test a specific nameserver.

<pre lang="bash">
dig @nameserver hostname
dig @nameserver ip-address

Other options.

<pre lang="bash">
dig hostname.domain.com +short
dig hostname.domain.com +noall +answer
dig @nameserver MX domain.com
dig @nameserver AAAA domain.com