The dig command is a common domain name query tool that can be used to test whether the domain name system is working properly
grammar
1 dig (options) (parameters)
Options
1 @ < server address > : specify the domain name server for domain name resolution; 2 - b < ip address > : when the host has multiple IP addresses, specify which IP address of the machine is used to send the domain name query request to the domain name server; 3 - f < file name > : specify that dig runs in batch mode, and the specified file saves the DNS task information that needs batch query; 4 - P: specifies the port number used by the domain name server; 5 - t < type > : specifies the Query DNS data type; 6 - x < IP address > : perform reverse domain name lookup; 7-4 : use IPv4; 8-6 : use IPv6; 9 - h : display command help information.
parameter
1 host: specify the host to query the domain name; 2 query type: specify the type of DNS query; 3 query class: specify the class to query DNS; 4 query options: specify query options.
example
[ root@Zhe_JinHua_EDU_01 data ] # dig @114 . 114.114 . 114 www.baidu.com ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.62.rc1.el6 <<>> @114.114.114.114 www.baidu.com ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46432 ;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;www.baidu.com. IN A ;; ANSWER SECTION: www.baidu.com. 116 IN CNAME www.a.shifen.com. www.a.shifen.com. 202 IN A 180.97.33.107 www.a.shifen.com. 202 IN A 180.97.33.108 ;; Query time: 58 msec ;; SERVER: 114.114.114.114#53(114.114.114.114) ;; WHEN: Tue Apr 17 02:44:40 2018 ;; MSG SIZE rcvd: 90