举荐浏览：每天学一个 Linux 命令（69）：nslookup
命令简介
dig 命令用于执行网络 DNS 查找。dig 是一个用于查问 DNS 名称服务器的灵便工具。它执行DNS查找并显示从查问的名称服务器返回的答案。
可应用 dig 来解决 DNS 问题，它具备灵活性，易用性和输入清晰度。相比其它工具性能更多、更弱小。
语法格局
dig [@server] [-b address] [-c class] [-f filename] [-k filename] [-m] [-p port#] [-q name] [-t type] [-x addr] [-y [hmac:]name:ke选项阐明
@<服务器地址> #指定进行域名解析的域名服务器-b #指定应用本机的哪个IP地址向域名服务器发送域名查问申请-f<文件名称> #指定dig以批处理的形式运行-P #指定域名服务器所应用端口号-t<类型> #指定要查问的DNS数据类型-x #执行逆向域名查问-4 #应用IPv4-6 #应用IPv6-h #显示帮忙信息利用举例
实例
[root@CentOS7-1 ~]# dig www.baidu.com; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.4 <<>> www.baidu.com;; global options: +cmd;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 57747;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 0;; QUESTION SECTION:;www.baidu.com. IN A;; ANSWER SECTION:www.baidu.com. 224 IN CNAME www.a.shifen.com.www.a.shifen.com. 224 IN A 36.152.44.95www.a.shifen.com. 224 IN A 36.152.44.96;; Query time: 27 msec;; SERVER: 223.5.5.5#53(223.5.5.5);; WHEN: Sat Mar 13 07:51:28 EST 2021;; MSG SIZE rcvd: 90逆向查问
[root@CentOS7-1 ~]# dig -x wwww.baidu.com; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.4 <<>> -x wwww.baidu.com;; global options: +cmd;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 7825;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0;; QUESTION SECTION:;com.baidu.wwww.in-addr.arpa. IN PTR;; AUTHORITY SECTION:in-addr.arpa. 600 IN SOA b.in-addr-servers.arpa. nstld.iana.org. 2021031279 1800 900 604800 3600;; Query time: 151 msec;; SERVER: 223.5.5.5#53(223.5.5.5);; WHEN: Sat Mar 13 07:52:54 EST 2021;; MSG SIZE rcvd: 113向指定的DNS服务器查问
[root@CentOS7-1 ~]# dig @8.8.8.8 baidu.com; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.4 <<>> @8.8.8.8 baidu.com; (1 server found);; global options: +cmd;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20803;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0;; QUESTION SECTION:;baidu.com. IN A;; ANSWER SECTION:baidu.com. 329 IN A 39.156.69.79baidu.com. 329 IN A 220.181.38.148;; Query time: 4 msec;; SERVER: 8.8.8.8#53(8.8.8.8);; WHEN: Sat Mar 13 07:55:26 EST 2021;; MSG SIZE rcvd: 59一次查问多少域名，将域名写入文件，而后从文件读取信息。
[root@CentOS7-1 ~]# cat domain_names_filewww.baidu.commail.163.comwww.qq.comwww.aliyun.comwww.amazon.com[root@CentOS7-1 ~]# dig +noall +answer -f domain_names_filewww.baidu.com. 70 IN CNAME www.a.shifen.com.www.a.shifen.com. 70 IN A 36.152.44.95www.a.shifen.com. 70 IN A 36.152.44.96mail.163.com. 117 IN CNAME ntes53.mail.163.com.ntes53.mail.163.com. 117 IN A 123.126.97.202www.qq.com. 71 IN CNAME ins-r23tsuuf.ias.tencent-cloud.net.ins-r23tsuuf.ias.tencent-cloud.net. 71 IN A 183.194.238.19ins-r23tsuuf.ias.tencent-cloud.net. 71 IN A 183.194.238.117www.aliyun.com. 44 IN CNAME www-jp-de-intl-adns.aliyun.com.www-jp-de-intl-adns.aliyun.com. 44 IN CNAME www-jp-de-intl-adns.aliyun.com.gds.alibabadns.com.www-jp-de-intl-adns.aliyun.com.gds.alibabadns.com. 44 IN CNAME sh.wagbridge.aliyun.aliyun.com.sh.wagbridge.aliyun.aliyun.com. 44 IN CNAME aliyun-adns.aliyun.com.aliyun-adns.aliyun.com. 44 IN CNAME aliyun-adns.aliyun.com.gds.alibabadns.com.aliyun-adns.aliyun.com.gds.alibabadns.com. 44 IN A 106.11.248.144www.amazon.com. 15 IN CNAME tp.47cf2c8c9-frontier.amazon.com.tp.47cf2c8c9-frontier.amazon.com. 15 IN CNAME d3ag4hukkh62yn.cloudfront.net.d3ag4hukkh62yn.cloudfront.net. 15 IN A 13.225.100.223#+noall（不显示所有内容）和 +answer（仅显示域名服务器的响应内容）#不应用任何参数，比照一下输入的后果[root@CentOS7-1 ~]# dig -f domain_names_file; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.4 <<>> www.baidu.com;; global options: +cmd;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 2834;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 0;; QUESTION SECTION:;www.baidu.com. IN A;; ANSWER SECTION:www.baidu.com. 86 IN CNAME www.a.shifen.com.www.a.shifen.com. 86 IN A 36.152.44.95www.a.shifen.com. 86 IN A 36.152.44.96;; Query time: 23 msec;; SERVER: 223.5.5.5#53(223.5.5.5);; WHEN: Sat Mar 13 08:02:46 EST 2021;; MSG SIZE rcvd: 90; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.4 <<>> mail.163.com;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 39346;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0;; QUESTION SECTION:;mail.163.com. IN A;; ANSWER SECTION:mail.163.com. 36 IN CNAME ntes53.mail.163.com.ntes53.mail.163.com. 36 IN A 123.126.97.202;; Query time: 19 msec;; SERVER: 223.5.5.5#53(223.5.5.5);; WHEN: Sat Mar 13 08:02:46 EST 2021;; MSG SIZE rcvd: 67; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.4 <<>> www.qq.com;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51368;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 0;; QUESTION SECTION:;www.qq.com. IN A;; ANSWER SECTION:www.qq.com. 78 IN CNAME ins-r23tsuuf.ias.tencent-cloud.net.ins-r23tsuuf.ias.tencent-cloud.net. 78 IN A 183.194.238.19ins-r23tsuuf.ias.tencent-cloud.net. 78 IN A 183.194.238.117;; Query time: 22 msec;; SERVER: 223.5.5.5#53(223.5.5.5);; WHEN: Sat Mar 13 08:02:46 EST 2021;; MSG SIZE rcvd: 108; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.4 <<>> www.aliyun.com;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 5856;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 0;; QUESTION SECTION:;www.aliyun.com. IN A;; ANSWER SECTION:www.aliyun.com. 22 IN CNAME www-jp-de-intl-adns.aliyun.com.www-jp-de-intl-adns.aliyun.com. 22 IN CNAME www-jp-de-intl-adns.aliyun.com.gds.alibabadns.com.www-jp-de-intl-adns.aliyun.com.gds.alibabadns.com. 22 IN CNAME sh.wagbridge.aliyun.aliyun.com.sh.wagbridge.aliyun.aliyun.com. 22 IN CNAME aliyun-adns.aliyun.com.aliyun-adns.aliyun.com. 22 IN CNAME aliyun-adns.aliyun.com.gds.alibabadns.com.aliyun-adns.aliyun.com.gds.alibabadns.com. 22 IN A 106.11.172.51;; Query time: 23 msec;; SERVER: 223.5.5.5#53(223.5.5.5);; WHEN: Sat Mar 13 08:02:46 EST 2021;; MSG SIZE rcvd: 228; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.4 <<>> www.amazon.com;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 36379;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 0;; QUESTION SECTION:;www.amazon.com. IN A;; ANSWER SECTION:www.amazon.com. 26 IN CNAME tp.47cf2c8c9-frontier.amazon.com.tp.47cf2c8c9-frontier.amazon.com. 26 IN CNAME www.amazon.com.edgekey.net.www.amazon.com.edgekey.net. 26 IN CNAME e15316.e22.akamaiedge.net.e15316.e22.akamaiedge.net. 26 IN A 223.119.142.58;; Query time: 22 msec;; SERVER: 223.5.5.5#53(223.5.5.5);; WHEN: Sat Mar 13 08:02:46 EST 2021;; MSG SIZE rcvd: 160