thm.de

Checked 22 October 2026, 00:40 UTC · via 8.8.8.8
!Passed with warnings
20 passed 3 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, dns1.fh-giessen.de, dns2.fh-giessen.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
deneb.dfn.de, dns1.fh-giessen.de, dns2.fh-giessen.de
NS in the zone
deneb.dfn.de, dns1.fh-giessen.de, dns2.fh-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-
dns1.fh-giessen.de212.201.18.47AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE212.201.18.47
dns2.fh-giessen.de212.201.18.48AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE212.201.18.48

Checks

  • ✓ 3 nameservers #6
    Delegated to deneb.dfn.de, dns1.fh-giessen.de, dns2.fh-giessen.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 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: dns1.fh-giessen.de, dns2.fh-giessen.de.
    #13

Nameservers

warn

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, 13 ms, authoritativenoyes / yesrefused0
dns1.fh-giessen.de 212.201.18.47NOERROR, 8 ms, authoritativenoyes / yesrefused9.18.49-1~deb12u2-Debian
dns2.fh-giessen.de 212.201.18.48NOERROR, 9 ms, authoritativenoyes / yesrefused9.18.49-1~deb12u2-Debian

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.
  • !
    Software version disclosed
    These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: dns1.fh-giessen.de: "9.18.49-1~deb12u2-Debian"; dns2.fh-giessen.de: "9.18.49-1~deb12u2-Debian". Hide or replace the version string.
    #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

warn

serial 2024089385 · primary dns1.fh-giessen.de

Found

Primary (MNAME)
dns1.fh-giessen.de
Contact (RNAME)
hostmaster.thm.de
Serial
2024089385
Refresh / retry
3600 s / 1800 s
Expire
1209600 s
Negative TTL
259200 s

Serial per nameserver

NameserverSerial
deneb.dfn.de (192.76.176.9)2024089385
deneb.dfn.de (2001:638:800:1::9)2024089385
dns1.fh-giessen.de (212.201.18.47)2024089385
dns2.fh-giessen.de (212.201.18.48)2024089385

Checks

  • ✓ Serial 2024089385 everywhere #22
    All nameservers serve the same version of the zone.
  • !
    Unusual SOA timers
    negative caching TTL (minimum) 3d is outside 5m–1d (RFC 2308 recommends 1–3 hours). Current values: refresh 1h, retry 30m, expire 14d, negative TTL 3d.
    #23
  • ✓ Primary is a public nameserver #24
    The primary nameserver dns1.fh-giessen.de is one of the listed nameservers.
  • ✓ Contact hostmaster@thm.de #25
    The SOA RNAME hostmaster.thm.de means hostmaster@thm.de.
  • ✓ Timestamp serial #26
    The serial 2024089385 is a Unix timestamp (2034-02-20 23:03 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
192.76.176.9:53
TypeValueTTL
SOAdns1.fh-giessen.de. hostmaster.thm.de. 2024089385 3600 1800 1209600 25920010800
NSdeneb.dfn.de.10800
NSdns1.fh-giessen.de.10800
NSdns2.fh-giessen.de.10800
A212.201.18.2610800
MX20 mxb.fh-giessen.de.10800
MX10 mx.fh-giessen.de.10800
TXT"google-site-verification=2CyeNU9tHrhFiiGRkDOxe728v8_IZcl5LhlC9pkDBr0"10800
TXT"adobe-idp-site-verification=9ec753aa5d921ed27d53a27558c97a2abfff7aa791ff0256aa80af1c6e80f83e"10800
TXT"cisco-ci-domain-verification=4b5bfc0a669bb8b736ad9d7bc5fcc23d6b69551a2fe7f11ff2b36cbb329dacf1"10800
TXT"v=spf1 include:spf.crsend.com ip4:212.201.0.0/20 ip4:212.201.16.0/23 ip4:212.201.18.0/24 ip4:212.201.24.0/21 ip4:212.201.19.0/25 ip4:212.201.19.128/26 ip4:141.100.10.0/24 ip6:2001:41b8:207:ffff::/64 ip6:2001:67c:2184:fdfe::/64 ?all"10800
TXT"ZOOM_verify_LD81NQgMjtbW3yqFiUxI3s"10800

Checks

  • ✓ TTLs within range #32
    TTLs: A 3h, MX 3h, NS 3h. The NS TTL at the parent is 1d and in the zone 3h; 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