Dig (domain information groper) - утилита для роботы с DNS серверами. Входит в состав BIND. При запуске она отображает свою версию программы, которая обычно совпадает с версией BIND. Опишу несколько моментов, как ней пользоваться:
Для того, чтобы просто получить IP-адрес по имени хоста необходимо выполнить:
[root@router ~]# dig unigx.org.ua
; <<>> DiG 9.4.2 <<>> unigx.org.ua
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37503
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1
;; QUESTION SECTION:
;unigx.org.ua. IN A
;; ANSWER SECTION:
unigx.org.ua. 3600 IN A 82.207.87.36
;; AUTHORITY SECTION:
unigx.org.ua. 3600 IN NS ns.unigx.org.ua.
unigx.org.ua. 3600 IN NS ns.yuren.com.ua.
;; ADDITIONAL SECTION:
ns.unigx.org.ua. 3600 IN A 82.207.87.36
;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Mon Dec 20 08:17:26 2010
;; MSG SIZE rcvd: 106
; <<>> DiG 9.4.2 <<>> unigx.org.ua
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37503
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1
;; QUESTION SECTION:
;unigx.org.ua. IN A
;; ANSWER SECTION:
unigx.org.ua. 3600 IN A 82.207.87.36
;; AUTHORITY SECTION:
unigx.org.ua. 3600 IN NS ns.unigx.org.ua.
unigx.org.ua. 3600 IN NS ns.yuren.com.ua.
;; ADDITIONAL SECTION:
ns.unigx.org.ua. 3600 IN A 82.207.87.36
;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Mon Dec 20 08:17:26 2010
;; MSG SIZE rcvd: 106
Для того, что бы получить доменное имя по IP-адресу (PTR-запись) для поиска в обратных зонах, необходимо DIG указать с параметром "-x":
[root@router ~]# dig -x 82.207.87.36
; <<>> DiG 9.4.2 <<>> -x 82.207.87.36
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46705
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1
;; QUESTION SECTION:
;36.87.207.82.in-addr.arpa. IN PTR
;; ANSWER SECTION:
36.87.207.82.in-addr.arpa. 67156 IN PTR mail.shzzch.com.
;; AUTHORITY SECTION:
87.207.82.in-addr.arpa. 16737 IN NS ns2.ukrtelecom.ua.
87.207.82.in-addr.arpa. 16737 IN NS expert.ukrtel.net.
;; ADDITIONAL SECTION:
expert.ukrtel.net. 5922 IN A 195.5.6.10
;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Mon Dec 20 08:21:46 2010
;; MSG SIZE rcvd: 150
; <<>> DiG 9.4.2 <<>> -x 82.207.87.36
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46705
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1
;; QUESTION SECTION:
;36.87.207.82.in-addr.arpa. IN PTR
;; ANSWER SECTION:
36.87.207.82.in-addr.arpa. 67156 IN PTR mail.shzzch.com.
;; AUTHORITY SECTION:
87.207.82.in-addr.arpa. 16737 IN NS ns2.ukrtelecom.ua.
87.207.82.in-addr.arpa. 16737 IN NS expert.ukrtel.net.
;; ADDITIONAL SECTION:
expert.ukrtel.net. 5922 IN A 195.5.6.10
;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Mon Dec 20 08:21:46 2010
;; MSG SIZE rcvd: 150
Для просмотра MX- записи для домена, необходимо указать парамерт "mx":
[root@router ~]# dig ya.ru mx
; <<>> DiG 9.4.2 <<>> ya.ru mx
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3248
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2
;; QUESTION SECTION:
;ya.ru. IN MX
;; ANSWER SECTION:
ya.ru. 592 IN MX 10 mx.yandex.ru.
;; AUTHORITY SECTION:
ya.ru. 162 IN NS ns1.yandex.ru.
ya.ru. 162 IN NS ns5.yandex.ru.
;; ADDITIONAL SECTION:
ns1.yandex.ru. 86602 IN A 213.180.193.1
ns5.yandex.ru. 86602 IN A 213.180.204.1
;; Query time: 202 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Mon Dec 20 08:57:47 2010
;; MSG SIZE rcvd: 117
; <<>> DiG 9.4.2 <<>> ya.ru mx
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3248
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2
;; QUESTION SECTION:
;ya.ru. IN MX
;; ANSWER SECTION:
ya.ru. 592 IN MX 10 mx.yandex.ru.
;; AUTHORITY SECTION:
ya.ru. 162 IN NS ns1.yandex.ru.
ya.ru. 162 IN NS ns5.yandex.ru.
;; ADDITIONAL SECTION:
ns1.yandex.ru. 86602 IN A 213.180.193.1
ns5.yandex.ru. 86602 IN A 213.180.204.1
;; Query time: 202 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Mon Dec 20 08:57:47 2010
;; MSG SIZE rcvd: 117
Для отображения только имени хоста, можно использовать параметр "+short":
[root@router ~]# dig -x 82.207.87.36 +short
mail.shzzch.com.
mail.shzzch.com.
По умолчанию в dig, отключен список поиска в /etc/resolv.conf, включаем с помощью опции в запросе "+search":
[root@router ~]# dig ya.ru +search +short
87.250.251.3
93.158.134.3
213.180.204.3
77.88.21.3
87.250.250.3
87.250.251.3
93.158.134.3
213.180.204.3
77.88.21.3
87.250.250.3
Для того, что бы узнать серийный номер зоны, запускаем с параметром "soa":
[root@router ~]# dig ya.ru soa +short
ns1.yandex.ru. sysadmin.yandex.ru. 2010121600 10800 900 2592000 900
ns1.yandex.ru. sysadmin.yandex.ru. 2010121600 10800 900 2592000 900
Если необходимо узнать версию DNS-сервера(не есть гуд!):
[root@router ~]# dig -t txt -c chaos VERSION.BIND @ns1.yandex.ru
; <<>> DiG 9.4.2 <<>> -t txt -c chaos VERSION.BIND @ns1.yandex.ru
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44195
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0
;; WARNING: recursion requested but not available
;; QUESTION SECTION:
;VERSION.BIND. CH TXT
;; ANSWER SECTION:
VERSION.BIND. 0 CH TXT "9.5.2-P4"
;; AUTHORITY SECTION:
VERSION.BIND. 0 CH NS VERSION.BIND.
;; Query time: 51 msec
;; SERVER: 213.180.193.1#53(213.180.193.1)
;; WHEN: Mon Dec 20 09:18:57 2010
;; MSG SIZE rcvd: 65
; <<>> DiG 9.4.2 <<>> -t txt -c chaos VERSION.BIND @ns1.yandex.ru
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44195
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0
;; WARNING: recursion requested but not available
;; QUESTION SECTION:
;VERSION.BIND. CH TXT
;; ANSWER SECTION:
VERSION.BIND. 0 CH TXT "9.5.2-P4"
;; AUTHORITY SECTION:
VERSION.BIND. 0 CH NS VERSION.BIND.
;; Query time: 51 msec
;; SERVER: 213.180.193.1#53(213.180.193.1)
;; WHEN: Mon Dec 20 09:18:57 2010
;; MSG SIZE rcvd: 65
Для проверки возможности копирования зоны с с master сервера на slave сервер:
[root@router ~]# dig @ns.yuren.com.ua unigx.org.ua. axfr
; <<>> DiG 9.4.2 <<>> @ns.yuren.com.ua unigx.org.ua. axfr
; (1 server found)
;; global options: printcmd
unigx.org.ua. 3600 IN SOA ns.unigx.org.ua. admin.shzzch.com. 2010112501 3600 900 3600000 3600
unigx.org.ua. 3600 IN NS ns.unigx.org.ua.
unigx.org.ua. 3600 IN NS ns.yuren.com.ua.
unigx.org.ua. 3600 IN A 82.207.87.36
files.unigx.org.ua. 3600 IN A 82.207.87.36
forum.unigx.org.ua. 3600 IN A 82.207.87.36
ftp.unigx.org.ua. 3600 IN A 82.207.87.36
ns.unigx.org.ua. 3600 IN A 82.207.87.36
www.unigx.org.ua. 3600 IN A 82.207.87.36
unigx.org.ua. 3600 IN SOA ns.unigx.org.ua. admin.shzzch.com. 2010112501 3600 900 3600000 3600
;; Query time: 462 msec
;; SERVER: 193.108.251.254#53(193.108.251.254)
;; WHEN: Mon Dec 20 09:43:04 2010
;; XFR size: 10 records (messages 1, bytes 278)
; <<>> DiG 9.4.2 <<>> @ns.yuren.com.ua unigx.org.ua. axfr
; (1 server found)
;; global options: printcmd
unigx.org.ua. 3600 IN SOA ns.unigx.org.ua. admin.shzzch.com. 2010112501 3600 900 3600000 3600
unigx.org.ua. 3600 IN NS ns.unigx.org.ua.
unigx.org.ua. 3600 IN NS ns.yuren.com.ua.
unigx.org.ua. 3600 IN A 82.207.87.36
files.unigx.org.ua. 3600 IN A 82.207.87.36
forum.unigx.org.ua. 3600 IN A 82.207.87.36
ftp.unigx.org.ua. 3600 IN A 82.207.87.36
ns.unigx.org.ua. 3600 IN A 82.207.87.36
www.unigx.org.ua. 3600 IN A 82.207.87.36
unigx.org.ua. 3600 IN SOA ns.unigx.org.ua. admin.shzzch.com. 2010112501 3600 900 3600000 3600
;; Query time: 462 msec
;; SERVER: 193.108.251.254#53(193.108.251.254)
;; WHEN: Mon Dec 20 09:43:04 2010
;; XFR size: 10 records (messages 1, bytes 278)
Проверим отдает ли DNS-сервер unigx.org.ua, зону unix.ck.ua:
vlymar@mops:~$ dig @unigx.org.ua unix.ck.ua
; <<>> DiG 9.4.3-P3 <<>> @unigx.org.ua unix.ck.ua
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20484
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1
;; WARNING: recursion requested but not available
;; QUESTION SECTION:
;unix.ck.ua. IN A
;; ANSWER SECTION:
unix.ck.ua. 3600 IN A 82.207.87.36
;; AUTHORITY SECTION:
unix.ck.ua. 3600 IN NS ns.yuren.com.ua.
unix.ck.ua. 3600 IN NS ns.unix.ck.ua.
;; ADDITIONAL SECTION:
ns.unix.ck.ua. 3600 IN A 82.207.87.36
;; Query time: 134 msec
;; SERVER: 82.207.87.36#53(82.207.87.36)
;; WHEN: Mon Dec 20 09:53:12 2010
;; MSG SIZE rcvd: 104
; <<>> DiG 9.4.3-P3 <<>> @unigx.org.ua unix.ck.ua
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20484
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1
;; WARNING: recursion requested but not available
;; QUESTION SECTION:
;unix.ck.ua. IN A
;; ANSWER SECTION:
unix.ck.ua. 3600 IN A 82.207.87.36
;; AUTHORITY SECTION:
unix.ck.ua. 3600 IN NS ns.yuren.com.ua.
unix.ck.ua. 3600 IN NS ns.unix.ck.ua.
;; ADDITIONAL SECTION:
ns.unix.ck.ua. 3600 IN A 82.207.87.36
;; Query time: 134 msec
;; SERVER: 82.207.87.36#53(82.207.87.36)
;; WHEN: Mon Dec 20 09:53:12 2010
;; MSG SIZE rcvd: 104
Dig посылает DNS-серверу unigx.org.ua, запрос SOA-записи для unix.ck.ua:
vlymar@mops:~$ dig @unigx.org.ua unix.ck.ua soa
; <<>> DiG 9.4.3-P3 <<>> @unigx.org.ua unix.ck.ua soa
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 32124
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1
;; WARNING: recursion requested but not available
;; QUESTION SECTION:
;unix.ck.ua. IN SOA
;; ANSWER SECTION:
unix.ck.ua. 3600 IN SOA ns.unix.ck.ua. admin.shzzch.com. 2010121901 3600 900 3600000 3600
;; AUTHORITY SECTION:
unix.ck.ua. 3600 IN NS ns.unix.ck.ua.
unix.ck.ua. 3600 IN NS ns.yuren.com.ua.
;; ADDITIONAL SECTION:
ns.unix.ck.ua. 3600 IN A 82.207.87.36
;; Query time: 185 msec
;; SERVER: 82.207.87.36#53(82.207.87.36)
;; WHEN: Mon Dec 20 10:01:55 2010
;; MSG SIZE rcvd: 140
; <<>> DiG 9.4.3-P3 <<>> @unigx.org.ua unix.ck.ua soa
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 32124
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1
;; WARNING: recursion requested but not available
;; QUESTION SECTION:
;unix.ck.ua. IN SOA
;; ANSWER SECTION:
unix.ck.ua. 3600 IN SOA ns.unix.ck.ua. admin.shzzch.com. 2010121901 3600 900 3600000 3600
;; AUTHORITY SECTION:
unix.ck.ua. 3600 IN NS ns.unix.ck.ua.
unix.ck.ua. 3600 IN NS ns.yuren.com.ua.
;; ADDITIONAL SECTION:
ns.unix.ck.ua. 3600 IN A 82.207.87.36
;; Query time: 185 msec
;; SERVER: 82.207.87.36#53(82.207.87.36)
;; WHEN: Mon Dec 20 10:01:55 2010
;; MSG SIZE rcvd: 140
Для того, что бы просмотреть трассу поиска информации в DNS, в dig предусмотрена опция "+trace":
[root@srv ~]# dig unix.ck.ua +trace
; <<>> DiG 9.6.2-P1 <<>> unix.ck.ua +trace
;; global options: +cmd
. 517876 IN NS b.root-servers.net.
. 517876 IN NS l.root-servers.net.
. 517876 IN NS k.root-servers.net.
. 517876 IN NS m.root-servers.net.
. 517876 IN NS h.root-servers.net.
. 517876 IN NS e.root-servers.net.
. 517876 IN NS a.root-servers.net.
. 517876 IN NS d.root-servers.net.
. 517876 IN NS g.root-servers.net.
. 517876 IN NS i.root-servers.net.
. 517876 IN NS c.root-servers.net.
. 517876 IN NS j.root-servers.net.
. 517876 IN NS f.root-servers.net.
;; Received 244 bytes from 127.0.0.1#53(127.0.0.1) in 2 ms
ua. 172800 IN NS cd1.ns.ua.
ua. 172800 IN NS he1.ns.ua.
ua. 172800 IN NS ho1.ns.ua.
ua. 172800 IN NS pch.ns.ua.
ua. 172800 IN NS ya1.ns.ua.
ua. 172800 IN NS ns-ua.ripe.net.
ua. 172800 IN NS sunic.sunet.se.
ua. 172800 IN NS sns-pb.isc.org.
;; Received 503 bytes from 199.7.83.42#53(l.root-servers.net) in 6 ms
ck.ua. 172800 IN NS ba1.ns.ua.
ck.ua. 172800 IN NS nix.net.ua.
ck.ua. 172800 IN NS ns.ctsense.net.
ck.ua. 172800 IN NS ns1.megastyle.com.
ck.ua. 172800 IN NS ns2.megastyle.com.
;; Received 164 bytes from 216.218.215.27#53(he1.ns.ua) in 227 ms
unix.ck.ua. 86400 IN NS ns.yuren.com.ua.
unix.ck.ua. 86400 IN NS ns.unigx.org.ua.
;; Received 82 bytes from 72.20.97.27#53(ba1.ns.ua) in 204 ms
unix.ck.ua. 3600 IN A 82.207.87.36
unix.ck.ua. 3600 IN NS ns.unigx.org.ua.
unix.ck.ua. 3600 IN NS ns.yuren.com.ua.
;; Received 114 bytes from 193.108.251.254#53(ns.yuren.com.ua) in 1 ms
; <<>> DiG 9.6.2-P1 <<>> unix.ck.ua +trace
;; global options: +cmd
. 517876 IN NS b.root-servers.net.
. 517876 IN NS l.root-servers.net.
. 517876 IN NS k.root-servers.net.
. 517876 IN NS m.root-servers.net.
. 517876 IN NS h.root-servers.net.
. 517876 IN NS e.root-servers.net.
. 517876 IN NS a.root-servers.net.
. 517876 IN NS d.root-servers.net.
. 517876 IN NS g.root-servers.net.
. 517876 IN NS i.root-servers.net.
. 517876 IN NS c.root-servers.net.
. 517876 IN NS j.root-servers.net.
. 517876 IN NS f.root-servers.net.
;; Received 244 bytes from 127.0.0.1#53(127.0.0.1) in 2 ms
ua. 172800 IN NS cd1.ns.ua.
ua. 172800 IN NS he1.ns.ua.
ua. 172800 IN NS ho1.ns.ua.
ua. 172800 IN NS pch.ns.ua.
ua. 172800 IN NS ya1.ns.ua.
ua. 172800 IN NS ns-ua.ripe.net.
ua. 172800 IN NS sunic.sunet.se.
ua. 172800 IN NS sns-pb.isc.org.
;; Received 503 bytes from 199.7.83.42#53(l.root-servers.net) in 6 ms
ck.ua. 172800 IN NS ba1.ns.ua.
ck.ua. 172800 IN NS nix.net.ua.
ck.ua. 172800 IN NS ns.ctsense.net.
ck.ua. 172800 IN NS ns1.megastyle.com.
ck.ua. 172800 IN NS ns2.megastyle.com.
;; Received 164 bytes from 216.218.215.27#53(he1.ns.ua) in 227 ms
unix.ck.ua. 86400 IN NS ns.yuren.com.ua.
unix.ck.ua. 86400 IN NS ns.unigx.org.ua.
;; Received 82 bytes from 72.20.97.27#53(ba1.ns.ua) in 204 ms
unix.ck.ua. 3600 IN A 82.207.87.36
unix.ck.ua. 3600 IN NS ns.unigx.org.ua.
unix.ck.ua. 3600 IN NS ns.yuren.com.ua.
;; Received 114 bytes from 193.108.251.254#53(ns.yuren.com.ua) in 1 ms
Для просмотра дополнительной текстовой информации о домене (запись TXT), необходимо выполнить:
[root@router /etc/rc.d]# dig unix.ck.ua txt | grep TXT
unix.ck.ua. 3600 IN TXT "v=spf1 include:_spf.google.com -all"