dig命令主要用来从dns域名服务器查询主机地址信息,与nslookup命令作用相同,但是比nslookup输出的信息更多。
安装dig
redhat系系统
yum install -y bind-utils
debian系系统
apt-get install -y dnsutils
如下查询新浪的dns解析
dig www.sina.com输出如下信息
现详细讲解下以上输出信息
; <<>> DiG 9.10.3-P4-Ubuntu <<>> www.sina.com
;; global options: +cmd
第一行至第二行:
dig的版本号,查询的域名,全局参数设置,默认是+cmd
命令以+nocmd作为参数,则该部分信息不显示
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 15886
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1
第三行至五行:从有关权威机构DNS 服务器收到响应的详细技术信息
opencode:操作码,QUER代表查询操作
status:状态,NOERROR则没有错误,代表着所请求的 DNS 服务器可以无障碍地服务于查询
id:编号,15886,16bit数字,dns协议中通过编号匹配返回和查询
flags:标志,可以出现可以不出现,不出则表示无标志
flags标志有qr,rd,ra,aa
qr:query,查询标志,代表查询操作
rd:recursion desired,代表希望通过递归查询操作
ra:recursive available,代表查询的服务器支持递归查询操作
aa:authoritative answer 权威回复(查询结果由管理域名的域名服务器提供,而不是缓存服务器提供的,称为权威回复)
QUERY:查询数,1代表有1个查询,对应下面的QUESTION SECTION中的记录数
ANSWER:结果数,3代表有3个结果,对应下面ANSWER SECTION中的记录数
AUTHORITY:权威域名服务器记录数,0代表该域名有0个权威域名服务器可供域名解析用
ADDITIONAL:额外记录数,1代表有1项额外记录
命令以+comments作为参数,可以不显示该部分
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
第六行至第七行:
有关 DNS 扩展机制(EDNS)的信息
命令以+noedns作为参数,可以不显示该部分
;; QUESTION SECTION:
;www.sina.com. IN A
第八行至第九行:
我们要查询的域名的输出信息,默认是A记录
命令以+noquestion作为参数,可以不显示该部分
;; ANSWER SECTION:
www.sina.com. 40 IN CNAME us.sina.com.cn.
us.sina.com.cn. 40 IN CNAME spool.grid.sinaedge.com.
spool.grid.sinaedge.com. 34 IN A 202.102.94.124
第十行至第十三行:
查询到的结果
可以看到www.sina.com 对应的ip为202.102.94.124
第一列为域名,第二列为TTL,缓存时间,单位秒,第三列为查询类别,A为A记录,CNAME为别名记录,第四列为解析的地址
命令以+noanswer作为参数,可以不显示该部分
;; Query time: 20 msec
;; SERVER: 114.114.114.114#53(114.114.114.114)
;; WHEN: Sun Aug 11 19:22:55 CST 2019
;; MSG SIZE rcvd: 119
第十四行至第十七行:有关查询的统计信息
Query time:查询耗时
SERVER:查询使用的服务器地址和端口
WHEN:查询的时间
MSG SIZE rcvd:回应的大小,收到了119字节
命令以+nostats作为参数,可以不显示该部分
dig相关的参数
+short 简单输出
[email protected]:~# dig +short www.sina.com
us.sina.com.cn.
spool.grid.sinaedge.com.
202.102.94.124
+noall +answer 返回详细信息,只返回查询结果
[email protected]:~# dig www.sina.com +noall +answer
; <<>> DiG 9.10.3-P4-Ubuntu <<>> www.sina.com +noall +answer
;; global options: +cmd
www.sina.com. 60 IN CNAME us.sina.com.cn.
us.sina.com.cn. 60 IN CNAME spool.grid.sinaedge.com.
spool.grid.sinaedge.com. 34 IN A 202.102.94.124
@x.x.x.x
从指定DNS服务器查询,默认dig 将主动使用 /etc/resolv.conf 文件中列出的 DNS 服务器来进行查询
[email protected]:~# dig @8.8.8.8 www.sina.com
; <<>> DiG 9.10.3-P4-Ubuntu <<>> @8.8.8.8 www.sina.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 36464
;; flags: qr rd ra; QUERY: 1, ANSWER: 9, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;www.sina.com. IN A
;; ANSWER SECTION:
www.sina.com. 59 IN CNAME us.sina.com.cn.
us.sina.com.cn. 59 IN CNAME wwwus.sina.com.
wwwus.sina.com. 59 IN CNAME ww1.sinaimg.cn.w.alikunlun.com.
ww1.sinaimg.cn.w.alikunlun.com. 59 IN A 205.204.104.186
ww1.sinaimg.cn.w.alikunlun.com. 59 IN A 205.204.104.195
ww1.sinaimg.cn.w.alikunlun.com. 59 IN A 47.246.16.229
ww1.sinaimg.cn.w.alikunlun.com. 59 IN A 47.91.195.229
ww1.sinaimg.cn.w.alikunlun.com. 59 IN A 47.246.16.230
ww1.sinaimg.cn.w.alikunlun.com. 59 IN A 47.246.16.231
;; Query time: 203 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Sun Aug 11 21:03:25 CST 2019
;; MSG SIZE rcvd: 226
指定查询类型
查询A记录(默认)
[email protected]:~# dig +nocmd www.sina.com a +noall +answer
www.sina.com. 49 IN CNAME us.sina.com.cn.
us.sina.com.cn. 49 IN CNAME spool.grid.sinaedge.com.
spool.grid.sinaedge.com. 48 IN A 202.102.94.124
查询CNAME记录
[email protected]:~# dig +nocmd www.sina.com cname +noall +answer
www.sina.com. 34 IN CNAME us.sina.com.cn.
查询txt记录
[email protected]:~# dig +nocmd google.com txt +noall +answer
google.com. 241 IN TXT "globalsign-smime-dv=CDYX+XFHUw2wml6/Gb8+59BsH31KzUr6c1l2BPvqKX8="
google.com. 241 IN TXT "docusign=05958488-4752-4ef2-95eb-aa7ba8a3bd0e"
google.com. 241 IN TXT "v=spf1 include:_spf.google.com ~all"
google.com. 241 IN TXT "docusign=1b0a6754-49b1-4db5-8540-d2c12664b289"
google.com. 241 IN TXT "facebook-domain-verification=22rm551cu4k0ab0bxsw536tlds4h95"
查询MX记录
[email protected]:~# dig +nocmd google.com mx +noall +answer
google.com. 428 IN MX 30 alt2.aspmx.l.google.com.
google.com. 428 IN MX 20 alt1.aspmx.l.google.com.
google.com. 428 IN MX 40 alt3.aspmx.l.google.com.
google.com. 428 IN MX 50 alt4.aspmx.l.google.com.
google.com. 428 IN MX 10 aspmx.l.google.com.
查询NS记录
[email protected]:~# dig +nocmd google.com ns +noall +answer
google.com. 121046 IN NS ns3.google.com.
google.com. 121046 IN NS ns2.google.com.
google.com. 121046 IN NS ns4.google.com.
google.com. 121046 IN NS ns1.google.com.
-x 反向查询,查询与特定 IP 地址关联的域名
[email protected]:~# dig -x 8.8.8.8 +noall +answer
; <<>> DiG 9.10.3-P4-Ubuntu <<>> -x 8.8.8.8 +noall +answer
;; global options: +cmd
8.8.8.8.in-addr.arpa. 79982 IN PTR dns.google.
+trace,跟踪查询过程
[email protected]:~# dig +trace www.sina.com
; <<>> DiG 9.10.3-P4-Ubuntu <<>> +trace www.sina.com
;; global options: +cmd
. 142304 IN NS d.root-servers.net.
. 142304 IN NS i.root-servers.net.
. 142304 IN NS l.root-servers.net.
. 142304 IN NS k.root-servers.net.
. 142304 IN NS j.root-servers.net.
. 142304 IN NS a.root-servers.net.
. 142304 IN NS m.root-servers.net.
. 142304 IN NS c.root-servers.net.
. 142304 IN NS f.root-servers.net.
. 142304 IN NS e.root-servers.net.
. 142304 IN NS g.root-servers.net.
. 142304 IN NS h.root-servers.net.
. 142304 IN NS b.root-servers.net.
;; Received 239 bytes from 114.114.114.114#53(114.114.114.114) in 20 ms
com. 172800 IN NS a.gtld-servers.net.
com. 172800 IN NS b.gtld-servers.net.
com. 172800 IN NS c.gtld-servers.net.
com. 172800 IN NS d.gtld-servers.net.
com. 172800 IN NS e.gtld-servers.net.
com. 172800 IN NS f.gtld-servers.net.
com. 172800 IN NS g.gtld-servers.net.
com. 172800 IN NS h.gtld-servers.net.
com. 172800 IN NS i.gtld-servers.net.
com. 172800 IN NS j.gtld-servers.net.
com. 172800 IN NS k.gtld-servers.net.
com. 172800 IN NS l.gtld-servers.net.
com. 172800 IN NS m.gtld-servers.net.
com. 86400 IN DS 30909 8 2 E2D3C916F6DEEAC73294E8268FB5885044A833FC5459588F4A9184CF C41A5766
com. 86400 IN RRSIG DS 8 1 86400 20190824050000 20190811040000 59944 . Au9ez+iicXM9ZCVNeBttnieOlMjtSLnFWS3fblB6yuJOPqAJDKlzGzH5 bo5A9agi+6ouB3di2J96Kdn2SE9Uq4mMaye4kQv7z7wUlthjwXadPAGq +nT4osIcOLxlWOCTLDBJnrCg6BnK7LoKMoleZjtQOr4ASNsW3CX3MEat SU/M+S9+Bg2NQeb+Z1rEieXIyG0zvlE+qzEg41rbuqFY3fk9kBMyB/sV 5lUeAZfAhlzH/jjKby+wJsaL+SRCPnstWgokekeZCHwXwJ4iHc2zRyCd 0e+FDT0z/7xouIYQVgt7GVQN0vQ/eUJBd9zhmCUbIfDi7w4AK9ykEJDU jVsVIg==
;; Received 1172 bytes from 198.97.190.53#53(h.root-servers.net) in 192 ms
sina.com. 172800 IN NS ns1.sina.com.cn.
sina.com. 172800 IN NS ns2.sina.com.cn.
sina.com. 172800 IN NS ns3.sina.com.cn.
sina.com. 172800 IN NS ns1.sina.com.
sina.com. 172800 IN NS ns2.sina.com.
sina.com. 172800 IN NS ns4.sina.com.
sina.com. 172800 IN NS ns3.sina.com.
CK0POJMG874LJREF7EFN8430QVIT8BSM.com. 86400 IN NSEC3 1 1 0 - CK0Q1GIN43N1ARRC9OSM6QPQR81H5M9A NS SOA RRSIG DNSKEY NSEC3PARAM
CK0POJMG874LJREF7EFN8430QVIT8BSM.com. 86400 IN RRSIG NSEC3 8 2 86400 20190815044522 20190808033522 17708 com. mZXFevDe/GAzLCPnKm123kkBDgeuHRJXSkMgsHkACMZmMmA5uCrvxXN8 7fTMTFFESSjd14PwgTavf5fJ4J4COTvIVHg7vrnztrt1JadLK3jXNPJ3 3Z8Cv5VINQMEPSAydR7XeZ8AMCvdkyEKB0jzpen719qTk4WWWAw33Jtw 9a8=
TGAG8VMC6NS5VVK68CIGRJ6Q414N2KB2.com. 86400 IN NSEC3 1 1 0 - TGAIBD36C6B9GMU6EB96HFA3PBUKS49B NS DS RRSIG
TGAG8VMC6NS5VVK68CIGRJ6Q414N2KB2.com. 86400 IN RRSIG NSEC3 8 2 86400 20190818052710 20190811041710 17708 com. XcB3H/b/3jb1ABIJ+ZF9o6PfwRjZsRuN1lue4f2RaRg41pINGot3s/oi itjHkSu4caYW8hxDpZDFWdsV8SRZFw54prByqOu8Bsuw0K9asjX/NEpH ehZov1MTBcJv0GoJN8+Vtj7GYVYuDWRT4LMJgNsfOitt5jTbEdHsVAhW 7XI=
;; Received 727 bytes from 192.26.92.30#53(c.gtld-servers.net) in 228 ms
www.sina.com. 60 IN CNAME us.sina.com.cn.
us.sina.com.cn. 60 IN CNAME spool.grid.sinaedge.com.
;; Received 103 bytes from 180.149.138.199#53(ns2.sina.com.cn) in 2 ms
dig批量查询
当有多个域名需要查询时,可以将要查询的域名写到一个文件,再统一查询
.digrc文件
如前面我们在命令行用到的+short,+noall,+answer等参数,我们可以写到当前用户家目录中的.digrc文件里(${home}/.digrc),这样当我们执行dig命令时就不需要再在命令行加这些参数了
原文地址:https://blog.51cto.com/13053917/2428661