uni-giessen.de

Checked 22 October 2026, 00:50 UTC · via 8.8.8.8
!Passed with warnings
21 passed 1 warning 0 failed 7 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, ns1.hrz.uni-giessen.de, ns2.hrz.uni-giessen.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
deneb.dfn.de, ns1.hrz.uni-giessen.de, ns2.hrz.uni-giessen.de
NS in the zone
deneb.dfn.de, ns1.hrz.uni-giessen.de, ns2.hrz.uni-giessen.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-
ns1.hrz.uni-giessen.de134.176.2.5AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.176.2.5
ns2.hrz.uni-giessen.de134.176.2.7AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.176.2.7

Checks

  • ✓ 3 nameservers #6
    Delegated to deneb.dfn.de, ns1.hrz.uni-giessen.de, ns2.hrz.uni-giessen.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: ns1.hrz.uni-giessen.de, ns2.hrz.uni-giessen.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: ns1.hrz.uni-giessen.de, ns2.hrz.uni-giessen.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
ns1.hrz.uni-giessen.de 134.176.2.5NOERROR, 4 ms, authoritativenoyes / yesrefusedNot supported
ns2.hrz.uni-giessen.de 134.176.2.7NOERROR, 5 ms, authoritativenoyes / yesrefusedNot supported

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"; ns1.hrz.uni-giessen.de: "Not supported"; ns2.hrz.uni-giessen.de: "Not supported".
    #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 2026092889 · primary ns1.hrz.uni-giessen.de

Found

Primary (MNAME)
ns1.hrz.uni-giessen.de
Contact (RNAME)
netzgrp.hrz.uni-giessen.de
Serial
2026092889
Refresh / retry
1800 s / 900 s
Expire
604800 s
Negative TTL
300 s

Serial per nameserver

NameserverSerial
deneb.dfn.de (192.76.176.9)2026092889
deneb.dfn.de (2001:638:800:1::9)2026092889
ns1.hrz.uni-giessen.de (134.176.2.5)2026092889
ns2.hrz.uni-giessen.de (134.176.2.7)2026092889

Checks

  • ✓ Serial 2026092889 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 30m, retry 15m, expire 7d, negative TTL 5m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns1.hrz.uni-giessen.de is one of the listed nameservers.
  • ✓ Contact netzgrp@hrz.uni-giessen.de #25
    The SOA RNAME netzgrp.hrz.uni-giessen.de means netzgrp@hrz.uni-giessen.de.
  • ✓ Date-based serial #26
    The serial 2026092889 follows the YYYYMMDDnn convention (2026-09-28).

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

14 records at the apex

Found

Read from
192.76.176.9:53
TypeValueTTL
SOAns1.hrz.uni-giessen.de. netzgrp.hrz.uni-giessen.de. 2026092889 1800 900 604800 3003600
NSns1.hrz.uni-giessen.de.3600
NSdeneb.dfn.de.3600
NSns2.hrz.uni-giessen.de.3600
A134.176.3.223600
MX10 mailgw00.uni-giessen.de.3600
TXT"seobility=c50b780a4f0c711e688bd681118ca6b6"3600
TXT"google-site-verification=wbKHlnY2i0EV-HGAdjK2M19HgwnR4_UbpNO_QbqgHwE"3600
TXT"_telesec-domain-validation=343475_2025-12-03_CZD0oOkGEQXd2VhR0tC98hKawPnjN6S0mWGjxY3n5lwbwiZRQO"3600
TXT"v=spf1 mx ip4:134.176.243.135/32 ip4:141.100.10.230/32 ip4:141.100.10.250/32 ip4:141.90.13.0/24 ip4:62.146.198.98/32 ~all"3600
TXT"google-site-verification=nYH2Be69GmP2btcc2acbRiiXrBjyGj9Yf7d6ExhlSlM"3600
TXT"anthropic-domain-verification-pj5ke1=R1afmZzDNHHPYUwQVqGqAEC9Z"3600
TXT"MS=3F613B143831BB8F881ED05E6FEDBF0DEBB18B69"3600
TXT"google-site-verification=0YpCp7vGkQho6pZg_iTw6MgaXPF0zHeg_LOTrwI8RQc"3600

Checks

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