nslookup example.com

$ nslookup example.com
Server:         192.168.0.1
Address:        192.168.0.1#53

Non-authoritative answer:
Name:   example.com
Address: 93.184.216.34

DNSサーバーを指定する場合
nslookup example.com DNS名

$ nslookup example.com A.IANA-SERVERS.NET
Server:         A.IANA-SERVERS.NET
Address:        199.43.135.53#53

Name:   example.com
Address: 93.184.216.34