hs-fulda.de

Checked 21 October 2026, 22:51 UTC · via 8.8.8.8
!Passed with warnings
27 passed 2 warnings 0 failed 4 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

dns-1.dfn.de, dns-3.dfn.de, ns01.rz.hs-fulda.de, ns02.rz.hs-fulda.de, ns03.rz.hs-fulda.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-1.dfn.de, dns-3.dfn.de, ns01.rz.hs-fulda.de, ns02.rz.hs-fulda.de, ns03.rz.hs-fulda.de
NS in the zone
dns-1.dfn.de, dns-3.dfn.de, ns01.rz.hs-fulda.de, ns02.rz.hs-fulda.de, ns03.rz.hs-fulda.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-3.dfn.de193.174.75.58 2001:638:d:b103::1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
ns01.rz.hs-fulda.de193.174.27.6 2001:638:301:10a::10AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE193.174.27.6 2001:638:301:10a::10
ns02.rz.hs-fulda.de193.174.27.38 2001:638:301:10b::10AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE193.174.27.38 2001:638:301:10b::10
ns03.rz.hs-fulda.de193.174.27.70 2001:638:301:10c::10AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE193.174.27.70 2001:638:301:10c::10

Checks

  • ✓ 5 nameservers #6
    Delegated to dns-1.dfn.de, dns-3.dfn.de, ns01.rz.hs-fulda.de, ns02.rz.hs-fulda.de, ns03.rz.hs-fulda.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: ns01.rz.hs-fulda.de, ns02.rz.hs-fulda.de, ns03.rz.hs-fulda.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 2 IPv6 /48s.
  • 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): 10 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

warn

10 of 10 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns-1.dfn.de 193.174.75.50NOERROR, 15 ms, authoritativenoyes / yesrefused0
dns-1.dfn.de 2001:638:d:b101::1NOERROR, 12 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 193.174.75.58NOERROR, 10 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 2001:638:d:b103::1NOERROR, 10 ms, authoritativenoyes / yesrefused0
ns01.rz.hs-fulda.de 193.174.27.6NOERROR, 6 ms, authoritativenoyes / yesrefusedKnot DNS 3.5.1
ns01.rz.hs-fulda.de 2001:638:301:10a::10NOERROR, 9 ms, authoritativenoyes / yesrefusedKnot DNS 3.5.1
ns02.rz.hs-fulda.de 193.174.27.38NOERROR, 6 ms, authoritativenoyes / yesrefusedKnot DNS 3.5.1
ns02.rz.hs-fulda.de 2001:638:301:10b::10NOERROR, 9 ms, authoritativenoyes / yesrefusedKnot DNS 3.5.1
ns03.rz.hs-fulda.de 193.174.27.70NOERROR, 6 ms, authoritativenoyes / yesrefusedKnot DNS 3.5.1
ns03.rz.hs-fulda.de 2001:638:301:10c::10NOERROR, 9 ms, authoritativenoyes / yesrefusedKnot DNS 3.5.1

Checks

  • ✓ All respond #14
    All 10 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: ns01.rz.hs-fulda.de: "Knot DNS 3.5.1"; ns02.rz.hs-fulda.de: "Knot DNS 3.5.1"; ns03.rz.hs-fulda.de: "Knot DNS 3.5.1". 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

pass

serial 2026102101 · primary ns01.rz.hs-fulda.de

Found

Primary (MNAME)
ns01.rz.hs-fulda.de
Contact (RNAME)
hostmaster.hs-fulda.de
Serial
2026102101
Refresh / retry
28800 s / 7200 s
Expire
604800 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
dns-1.dfn.de (193.174.75.50)2026102101
dns-1.dfn.de (2001:638:d:b101::1)2026102101
dns-3.dfn.de (193.174.75.58)2026102101
dns-3.dfn.de (2001:638:d:b103::1)2026102101
ns01.rz.hs-fulda.de (193.174.27.6)2026102101
ns01.rz.hs-fulda.de (2001:638:301:10a::10)2026102101
ns02.rz.hs-fulda.de (193.174.27.38)2026102101
ns02.rz.hs-fulda.de (2001:638:301:10b::10)2026102101
ns03.rz.hs-fulda.de (193.174.27.70)2026102101
ns03.rz.hs-fulda.de (2001:638:301:10c::10)2026102101

Checks

  • ✓ Serial 2026102101 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 8h, retry 2h, expire 7d, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns01.rz.hs-fulda.de is one of the listed nameservers.
  • ✓ Contact hostmaster@hs-fulda.de #25
    The SOA RNAME hostmaster.hs-fulda.de means hostmaster@hs-fulda.de.
  • ✓ Date-based serial #26
    The serial 2026102101 follows the YYYYMMDDnn convention (2026-10-21).

DNSSEC

warn

Signed, DS published at parent

Found

Validated by resolver
yes
Denial of existence
NSEC3
NSEC3
0 iterations, 0-byte salt
Signatures valid until
23 October 2026

DS at the parent

Key tagAlgorithmDigestMatches a key
50720ECDSAP256SHA256 (13)SHA256 AF23FD2916DFB58D…yes

DNSKEY in the zone

Key tagRoleAlgorithm
9147ZSK (256)ECDSAP256SHA256 (13)
50720KSK (257)ECDSAP256SHA256 (13)

Checks

  • ✓ Signed and validated #27
    The zone is signed, the parent publishes a DS record, and the resolver validates the answers.
  • ✓ DS matches a key #28
    The DS record at the parent matches a key in the zone: key tag 50720 (SHA256).
  • ✓ Modern algorithms #29
    Key algorithms: ECDSAP256SHA256 (13).
  • !
    Signatures expire soon
    The earliest signature expires at 2026-10-23 10:47 UTC (in 36h0m0s). Check that automatic re-signing works.
    #30
  • ✓ NSEC3 as recommended #31
    The zone uses NSEC3 with 0 iterations and no salt (RFC 9276).

Records

pass

17 records at the apex

Found

Read from
193.174.75.50:53
TypeValueTTL
SOAns01.rz.hs-fulda.de. hostmaster.hs-fulda.de. 2026102101 28800 7200 604800 36003600
NSdns-1.dfn.de.3600
NSns02.rz.hs-fulda.de.3600
NSns01.rz.hs-fulda.de.3600
NSns03.rz.hs-fulda.de.3600
NSdns-3.dfn.de.3600
A13.93.52.1323600
MX10 a1621.mx.srv.dfn.de.3600
MX10 b1621.mx.srv.dfn.de.3600
MX10 c1621.mx.srv.dfn.de.3600
TXT"cisco-ci-domain-verification=90d0f4556f19bf6d708033e65d90f78ea41fc516e2dbe165e3fbc0f8f257568"3600
TXT"v=spf1 include:spf.rz.hs-fulda.de -all"3600
TXT"google-site-verification=kl8rSof43Z28B6Zj8TnJLs2RFetgaNNBewf8i3Hc17Q"3600
CAA0 issue "letsencrypt.org"3600
CAA0 issue "harica.gr"3600
CAA0 issuewild ";"3600
CAA0 issue "pki.dfn.de"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.
  • ✓ CAA restricts issuance #35
    Certificates may be issued by: letsencrypt.org, harica.gr, none (issuance forbidden), pki.dfn.de.