gbv.de

Checked 21 October 2026, 22:32 UTC · via 8.8.8.8
!Passed with warnings
21 passed 2 warnings 0 failed 6 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

deneb.dfn.de, inets1.gbv.de, inets2.gbv.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
deneb.dfn.de, inets1.gbv.de, inets2.gbv.de
NS in the zone
deneb.dfn.de, inets1.gbv.de, inets2.gbv.de
NameserverAddressesNetwork (AS)Glue
deneb.dfn.de192.76.176.9 2001:638:800:1::9AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
inets1.gbv.de193.174.240.41AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE193.174.240.41
inets2.gbv.de193.174.240.42AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE193.174.240.42

Checks

  • ✓ 3 nameservers #6
    Delegated to deneb.dfn.de, inets1.gbv.de, inets2.gbv.de.
  • ✓ Parent and zone agree #7
    The parent delegation and the zone's NS records list the same nameservers.
  • ✓ Glue present and correct #8
    Glue is published for the nameservers inside the zone: inets1.gbv.de, inets2.gbv.de.
  • ✓ 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 1 IPv6 /48.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE): 4 addresses). An outage or attack on that network affects all nameservers; large anycast providers mitigate this, but a secondary DNS provider adds independence.
    #11
  • 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: inets1.gbv.de, inets2.gbv.de.
    #13

Nameservers

info

4 of 4 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
deneb.dfn.de 192.76.176.9NOERROR, 14 ms, authoritativenoyes / yesrefused0
deneb.dfn.de 2001:638:800:1::9NOERROR, 14 ms, authoritativenoyes / yesrefused0
inets1.gbv.de 193.174.240.41NOERROR, 10 ms, authoritativenoyes / yesrefused-
inets2.gbv.de 193.174.240.42NOERROR, 9 ms, authoritativenoyes / yesrefused-

Checks

  • ✓ All respond #14
    All 4 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.
  • i
    Identifying string disclosed
    These nameservers answer version queries with a string that is not a version number: deneb.dfn.de: "0".
    #17
  • ✓ 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 2021094983 · primary inets1.gbv.de

Found

Primary (MNAME)
inets1.gbv.de
Contact (RNAME)
hostmaster.gbv.de
Serial
2021094983
Refresh / retry
28800 s / 7200 s
Expire
604800 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
deneb.dfn.de (192.76.176.9)2021094983
deneb.dfn.de (2001:638:800:1::9)2021094983
inets1.gbv.de (193.174.240.41)2021094983
inets2.gbv.de (193.174.240.42)2021094983

Checks

  • ✓ Serial 2021094983 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 8h, retry 2h, expire 7d, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver inets1.gbv.de is one of the listed nameservers.
  • ✓ Contact hostmaster@gbv.de #25
    The SOA RNAME hostmaster.gbv.de means hostmaster@gbv.de.
  • ✓ Timestamp serial #26
    The serial 2021094983 is a Unix timestamp (2034-01-17 07:16 UTC).

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

warn

14 records at the apex

Found

Read from
192.76.176.9:53
TypeValueTTL
SOAinets1.gbv.de. hostmaster.gbv.de. 2021094983 28800 7200 604800 8640086400
NSinets2.gbv.de.86400
NSinets1.gbv.de.86400
NSdeneb.dfn.de.86400
A193.174.240.19986400
MX50 b1234.mx.srv.dfn.de.60
MX10 a1234.mx.srv.dfn.de.60
MX50 c1234.mx.srv.dfn.de.60
TXT"OSSRH-73866"86400
TXT"v=spf1 ip4:193.174.240.41 ip4:193.174.240.42 ip4:193.174.240.101 include:spf.gwdg.de ~all"86400
TXT"atlassian-domain-verification=2cKsEPSyPHhsCe4xAUTvRrEWZRBQvmgIkBP7z43zpvjLYP3V9ZY2XiOX3nHkPS5t"86400
CAA0 issue "letsencrypt.org"3600
CAA0 issue "sectigo.com"3600
CAA0 issue "harica.gr"3600

Checks

  • !
    Very low TTLs
    These records have a TTL below 5m, causing extra queries and slower lookups: MX (1m). Low TTLs are useful just before a planned change.
    #32
  • ✓ No CNAME at the apex #33
    The zone apex has no CNAME record.
  • ✓ No wildcard #34
    Names that don't exist return NXDOMAIN.
  • ✓ CAA restricts issuance #35
    Certificates may be issued by: letsencrypt.org, sectigo.com, harica.gr.