dns


Whois - domaine information


Whois records are used to get details provided by the domain owner to domain registrar. Whois serves are operated by Regional Internet Registrars (RIR) and use port 43. In Linux we can use the command whois. We can use DNS to find services, like mails, or subdomaines.

$ whois orange.fr
registrar:   ORANGE
type:        Isp Option 1
address:     78 Rue Olivier de Serres
address:     78-84
address:     75015 PARIS 15
country:     FR
phone:       +33 1 53 95 12 28
e-mail:      domaine.admin@orange.com
website:     https://cloud.orange-business.com/fr/e-boutique/noms-de-domaine
anonymous:   NO
registered:  2006-02-15T12:00:00Z
source:      FRNIC

nic-hdl:     O7771-FRNIC
type:        ORGANIZATION
contact:     ORANGE
address:     ORANGE
address:     78-84, rue Olivier de Serres
address:     75015 Paris
country:     FR
phone:       +33 1 44 44 22 22
fax-no:      +33 1 45 30 52 71
e-mail:      gestionndd@francetelecom.biz
registrar:   ORANGE
changed:     2018-02-21T08:11:58Z nic@nic.fr
anonymous:   NO
obsoleted:   NO
eligstatus:  not identified
reachstatus: not identified
source:      FRNIC
...

Zone transfer using dig


To create replication of DNS server, we use zone transfer to synchronize the data. A zone transfer request is a copu of the database with IP-hostname that it can resolve. A misconfiguration in DNS servers allow for anyone to ask for a zone transfer and obtain the full database with the dig (Domain Internet Groper) command. Zone transfer use TCP port 53 and not UDP port 53 (standard). Exists many types of DNS records, like Mail Exchanger (MX), SRV, PTR.

$ dig google.fr mx
;; ANSWER SECTION:
google.fr.              582     IN      MX      50 alt4.aspmx.l.google.com.
google.fr.              582     IN      MX      40 alt3.aspmx.l.google.com.
google.fr.              582     IN      MX      10 aspmx.l.google.com.
google.fr.              582     IN      MX      30 alt2.aspmx.l.google.com.
google.fr.              582     IN      MX      20 alt1.aspmx.l.google.com.
# make zone transfer request
$ dig axfr zonetransfer.me @nsztm1.digi.ninja
# axfr: zone transfer from zonetransfer.me domain to nsztm1.digi.ninja server
zonetransfer.me.        7200    IN      SOA     nsztm1.digi.ninja. robin.digi.ninja. 2017042001 172800 900 1209600 3600                                                             
zonetransfer.me.        300     IN      HINFO   "Casio fx-700G" "Windows XP"
zonetransfer.me.        301     IN      TXT     "google-site-verification=tyP28J7JAUHA9fw2sHXMgcCC0I6XBmmoVi04VlMewxA"
zonetransfer.me.        7200    IN      MX      0 ASPMX.L.GOOGLE.COM.
zonetransfer.me.        7200    IN      MX      10 ALT1.ASPMX.L.GOOGLE.COM.
zonetransfer.me.        7200    IN      MX      10 ALT2.ASPMX.L.GOOGLE.COM.
zonetransfer.me.        7200    IN      MX      20 ASPMX2.GOOGLEMAIL.COM.
zonetransfer.me.        7200    IN      MX      20 ASPMX3.GOOGLEMAIL.COM.
zonetransfer.me.        7200    IN      MX      20 ASPMX4.GOOGLEMAIL.COM.
zonetransfer.me.        7200    IN      MX      20 ASPMX5.GOOGLEMAIL.COM.
zonetransfer.me.        7200    IN      A       5.196.105.14
zonetransfer.me.        7200    IN      NS      nsztm1.digi.ninja.
zonetransfer.me.        7200    IN      NS      nsztm2.digi.ninja.
_sip._tcp.zonetransfer.me. 14000 IN     SRV     0 0 5060 www.zonetransfer.me.
14.105.196.5.IN-ADDR.ARPA.zonetransfer.me. 7200 IN PTR www.zonetransfer.me.
asfdbauthdns.zonetransfer.me. 7900 IN   AFSDB   1 asfdbbox.zonetransfer.me.
asfdbbox.zonetransfer.me. 7200  IN      A       127.0.0.1
asfdbvolume.zonetransfer.me. 7800 IN    AFSDB   1 asfdbbox.zonetransfer.me.
canberra-office.zonetransfer.me. 7200 IN A      202.14.81.230
cmdexec.zonetransfer.me. 300    IN      TXT     "; ls"
contact.zonetransfer.me. 2592000 IN     TXT     "Remember to call or email Pippa on +44 123 4567890 or pippa@zonetransfer.me when making DNS changes"                              
dc-office.zonetransfer.me. 7200 IN      A       143.228.181.132
deadbeef.zonetransfer.me. 7201  IN      AAAA    dead:beaf::
dr.zonetransfer.me.     300     IN      LOC     53 20 56.558 N 1 38 33.526 W 0.00m 1m 10000m 10m
DZC.zonetransfer.me.    7200    IN      TXT     "AbCdEfG"
email.zonetransfer.me.  2222    IN      NAPTR   1 1 "P" "E2U+email" "" email.zonetransfer.me.zonetransfer.me.
email.zonetransfer.me.  7200    IN      A       74.125.206.26
home.zonetransfer.me.   7200    IN      A       127.0.0.1
# locked transfer
$ dig axfr facebook.com @nsztm1.digi.ninja
; Transfer failed.

Sometimes, the primary DNS server block the zone transfer, and a secondary server will allow it.

# all nameservers of a domain
$ dig google.com NS +noall +answer
google.com.             16907   IN      NS      ns2.google.com.
google.com.             16907   IN      NS      ns3.google.com.
google.com.             16907   IN      NS      ns1.google.com.
google.com. 						16907   IN      NS      ns4.google.com.