admin@MEmini-Cat:/$ nslookup www.baidu.com
Server: 223.5.5.5
Address: 223.5.5.5#53
Non-authoritative answer:
www.baidu.com canonical name = www.a.shifen.com.
Name: www.a.shifen.com
Address: 220.181.111.1
Name: www.a.shifen.com
Address: 220.181.111.232
Name: www.a.shifen.com
Address: 240e:83:205:381:0:ff:b00f:96a2
Name: www.a.shifen.com
Address: 240e:83:205:1cd:0:ff:b0b8:dee9
admin@MEmini-Cat:/$ nslookup docker.mirrors.tuna.tsinghua.edu.cn
Server: 223.5.5.5
Address: 223.5.5.5#53
** server can't find docker.mirrors.tuna.tsinghua.edu.cn: NXDOMAIN