DNS
nslookup
Query DNS records and troubleshoot DNS issues.
Explanation
Nslookup asks a DNS server for records about a domain. It helps confirm whether a domain resolves, which DNS server answered, and whether DNS is the reason a site will not load.
Syntax
nslookup <domain>
Look up a domain
nslookup google.com
Use this to confirm whether DNS returns an address.
Ask a specific resolver
nslookup google.com 1.1.1.1
Compare your default DNS server with a public resolver.