Nslookup

we can use nslookup to send queries in much the same way that resolvers do.

  • we can also use it to query other nameservers as a nameserver would

The biggest difference between nslookup’s behavior and the resolver’s behavior is that nslookup talks to only one nameserver at a time.

  • in /etc/resolv.conf, if there are 2 nameservers listed, then the resolver will try the first, then the second. On the other hand, nslookup will only ever try the first.

By default, nslookup looks up A records

  • if you type in an IP address (and the nslookup query type is A or PTR), nslookup inverts the address, appends in-addr.arpa, and looks up PTR records instead

We can also use https://dnslookup.online