mpifg.de

Checked 21 October 2026, 23:30 UTC · via 8.8.8.8
!Passed with warnings
23 passed 1 warning 0 failed 5 info

Registration

info

.de country-code

Found

TLD
.de (country-code)
ICANN policies apply
no

Checks

  • i
    .de is a country-code TLD (ccTLD)
    Country-code TLD: governed by its local registry under national policy, not by an ICANN contract. Registrar accreditation, dispute resolution and RDAP/WHOIS rules are set by the registry.
    #1
  • ✓ TLD delegated and signed #2
    .de is delegated in the root zone and DNSSEC-signed.
  • i
    Registration data not available
    No registration data via RDAP: the registry of .de offers no RDAP service. Many ccTLD registries don't offer RDAP; check the registry's WHOIS instead.
    #3

Delegation

info

dns1.gwdg.de, dns2.gwdg.de, dns3.gwdg.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns1.gwdg.de, dns2.gwdg.de, dns3.gwdg.de
NS in the zone
dns1.gwdg.de, dns2.gwdg.de, dns3.gwdg.de
NameserverAddressesNetwork (AS)Glue
dns1.gwdg.de134.76.33.41 2a06:93c7:e1::1AS207592 GOENET - Gesellschaft fuer wissenschaftliche Datenverarbeitung mbH, Goettingen, DE AS207592 GOENET - Gesellschaft fuer wissenschaftliche Datenverarbeitung mbH, Goettingen, DE134.76.33.41 2a06:93c7:e1::1
dns2.gwdg.de134.76.33.42 2a06:93c7:e2::1AS207592 GOENET - Gesellschaft fuer wissenschaftliche Datenverarbeitung mbH, Goettingen, DE AS207592 GOENET - Gesellschaft fuer wissenschaftliche Datenverarbeitung mbH, Goettingen, DE134.76.33.42 2a06:93c7:e2::1
dns3.gwdg.de193.175.210.140AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE193.175.210.140

Checks

  • ✓ 3 nameservers #6
    Delegated to dns1.gwdg.de, dns2.gwdg.de, dns3.gwdg.de.
  • ✓ Parent and zone agree #7
    The parent delegation and the zone's NS records list the same nameservers.
  • ✓ No glue needed #8
    All nameservers are outside the zone, so no glue records are needed.
  • ✓ All names resolve #9
    Every nameserver name has an address and is not an alias.
  • ✓ Nameservers in different networks #10
    The nameservers are spread over 2 IPv4 /24s and 2 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS207592 (GOENET - Gesellschaft fuer wissenschaftliche Datenverarbeitung mbH, Goettingen, DE): 4 addresses; AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE): 1 address.
  • i
    All nameserver names under .de
    All nameserver names are under one TLD, so a problem with that TLD also makes the nameservers unreachable. Some operators use names under two TLDs for extra resilience.
    #12
  • i
    Partly IPv6
    These nameservers have no IPv6 address: dns3.gwdg.de.
    #13

Nameservers

pass

5 of 5 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns1.gwdg.de 134.76.33.41NOERROR, 7 ms, authoritativenoyes / yesrefused-
dns1.gwdg.de 2a06:93c7:e1::1NOERROR, 7 ms, authoritativenoyes / yesrefused-
dns2.gwdg.de 134.76.33.42NOERROR, 7 ms, authoritativenoyes / yesrefused-
dns2.gwdg.de 2a06:93c7:e2::1NOERROR, 8 ms, authoritativenoyes / yesrefused-
dns3.gwdg.de 193.175.210.140NOERROR, 13 ms, authoritativenoyes / yesrefused-

Checks

  • ✓ All respond #14
    All 5 nameserver addresses answered.
  • ✓ All authoritative #15
    Every responding nameserver answers authoritatively for the zone.
  • ✓ No recursion #16
    The nameservers do not answer recursive queries for other domains.
  • ✓ No version disclosed #17
    The nameservers don't reveal their software version.
  • ✓ Zone transfers refused #18
    No nameserver allows a zone transfer to the public.
  • ✓ TCP supported #19
    All nameservers answer over TCP.
  • ✓ EDNS supported #20
    All nameservers support EDNS(0).
  • ✓ Public addresses #21
    All nameserver addresses are publicly routable.

SOA

pass

serial 724327074 · primary dns1.gwdg.de

Found

Primary (MNAME)
dns1.gwdg.de
Contact (RNAME)
hostmaster.gwdg.de
Serial
724327074
Refresh / retry
21600 s / 3600 s
Expire
2419200 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
dns1.gwdg.de (134.76.33.41)724327074
dns1.gwdg.de (2a06:93c7:e1::1)724327074
dns2.gwdg.de (134.76.33.42)724327074
dns2.gwdg.de (2a06:93c7:e2::1)724327074
dns3.gwdg.de (193.175.210.140)724327074

Checks

  • ✓ Serial 724327074 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 6h, retry 1h, expire 28d, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver dns1.gwdg.de is one of the listed nameservers.
  • ✓ Contact hostmaster@gwdg.de #25
    The SOA RNAME hostmaster.gwdg.de means hostmaster@gwdg.de.
  • ✓ Counter serial #26
    The serial 724327074 is a plain counter.

DNSSEC

warn

Not signed

Found

Validated by resolver
no

Checks

  • !
    Not signed
    The zone is not signed with DNSSEC, so answers can be spoofed. Enable DNSSEC at your DNS provider and publish the DS record at your registrar.
    #27

Records

info

11 records at the apex

Found

Read from
134.76.33.41:53
TypeValueTTL
SOAdns1.gwdg.de. hostmaster.gwdg.de. 724327074 21600 3600 2419200 360060
NSdns3.gwdg.de.86400
NSdns1.gwdg.de.86400
NSdns2.gwdg.de.86400
A134.76.31.2053600
MX10 c1232.mx.srv.dfn.de.3600
MX10 b1232.mx.srv.dfn.de.3600
MX10 a1232.mx.srv.dfn.de.3600
TXT"MS=ms35751287"3600
TXT"cisco-ci-domain-verification=68d0c35dfbaed6ba1ff33d7454d09d539ed447902fde66af482de281c8a29990"3600
TXT"v=spf1 mx include:spf.gwdg.de ip4:192.124.250.3 a:mail.mpifg.de ~all"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 1h, MX 1h, NS 1d.
  • ✓ No CNAME at the apex #33
    The zone apex has no CNAME record.
  • ✓ No wildcard #34
    Names that don't exist return NXDOMAIN.
  • i
    No CAA records
    Without CAA records any certificate authority may issue certificates for this domain. A CAA record limits issuance to the CAs you use.
    #35