hs-harz.de

Checked 21 October 2026, 22:51 UTC · via 8.8.8.8
!Passed with warnings
19 passed 2 warnings 0 failed 8 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

warn

dns-1.dfn.de, dns-2.dfn.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-1.dfn.de, dns-2.dfn.de
NS in the zone
dns-1.dfn.de, dns-2.dfn.de
NameserverAddressesNetwork (AS)Glue
dns-1.dfn.de193.174.75.50 2001:638:d:b101::1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
dns-2.dfn.de193.174.75.54 2001:638:d:b102::1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: dns-1.dfn.de, dns-2.dfn.de.
    #6
  • ✓ 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 one network
    all IPv4 addresses are in 193.174.75.0/24; all IPv6 addresses are in 2001:638:d::/48. A single network failure takes all nameservers down; RFC 2182 recommends topologically separate networks (anycast setups are an exception).
    #10
  • 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
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

info

4 of 4 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns-1.dfn.de 193.174.75.50NOERROR, 12 ms, authoritativenoyes / yesrefused0
dns-1.dfn.de 2001:638:d:b101::1NOERROR, 14 ms, authoritativenoyes / yesrefused0
dns-2.dfn.de 193.174.75.54NOERROR, 7 ms, authoritativenoyes / yesrefused0
dns-2.dfn.de 2001:638:d:b102::1NOERROR, 6 ms, authoritativenoyes / yesrefused0

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: dns-1.dfn.de: "0"; dns-2.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

info

serial 2024480666 · primary deneb.dfn.de

Found

Primary (MNAME)
deneb.dfn.de
Contact (RNAME)
dns-support.hs-harz.de
Serial
2024480666
Refresh / retry
10800 s / 3600 s
Expire
2419200 s
Negative TTL
900 s

Serial per nameserver

NameserverSerial
dns-1.dfn.de (193.174.75.50)2024480666
dns-1.dfn.de (2001:638:d:b101::1)2024480666
dns-2.dfn.de (193.174.75.54)2024480666
dns-2.dfn.de (2001:638:d:b102::1)2024480666

Checks

  • ✓ Serial 2024480666 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 3h, retry 1h, expire 28d, negative TTL 15m.
  • i
    Hidden master
    The primary nameserver deneb.dfn.de is not listed as a nameserver: a hidden master that only feeds the public secondaries. That is a common setup; make sure it is not reachable for zone transfers from outside.
    #24
  • ✓ Contact dns-support@hs-harz.de #25
    The SOA RNAME dns-support.hs-harz.de means dns-support@hs-harz.de.
  • ✓ Timestamp serial #26
    The serial 2024480666 is a Unix timestamp (2034-02-25 11:44 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

info

12 records at the apex

Found

Read from
193.174.75.50:53
TypeValueTTL
SOAdeneb.dfn.de. dns-support.hs-harz.de. 2024480666 10800 3600 2419200 90028800
NSdns-1.dfn.de.28800
NSdns-2.dfn.de.28800
A193.175.32.9628800
MX10 a1781.mx.srv.dfn.de.3600
MX10 c1781.mx.srv.dfn.de.3600
MX10 b1781.mx.srv.dfn.de.3600
TXT"v=spf1 ip4:194.95.195.92 include:_spf.tivian.com ~all"300
TXT"google-site-verification=8gOc05s28-uM0AMrxGIGhqReJF7PRWHa071f1q1K58M"300
TXT"HARICA-Kj6KholbJMiV33aMqJf"300
TXT"MS=185545076A02FFA5AF6088FCA469A39D2B81427E"300
TXT"adobe-idp-site-verification=86b176056fba990debd836c9e7680781acf93cf3ad76b4a8f2abe430cf9bb9fa"300

Checks

  • ✓ TTLs within range #32
    TTLs: A 8h, MX 1h, NS 8h. The NS TTL at the parent is 1d and in the zone 8h; resolvers may use either.
  • ✓ 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