museum-folkwang.de

Checked 21 October 2026, 23:31 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

warn

ns1.werk21system.de, ns2.werk21system.de, ns3.werk21system.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
ns1.werk21system.de, ns2.werk21system.de, ns3.werk21system.de
NS in the zone
ns1.werk21system.de, ns2.werk21system.de, ns3.werk21system.de
NameserverAddressesNetwork (AS)Glue
ns1.werk21system.de149.233.9.125AS203329 ESHELTER - NTT Global Data Centers EMEA GmbH, DE149.233.9.125
ns2.werk21system.de49.13.240.49AS24940 HETZNER-AS - Hetzner Online GmbH, DE49.13.240.49
ns3.werk21system.de91.216.245.193AS48314 IP-PROJECTS - Michael Sebastian Schinzel trading as IP-Projects GmbH & Co. KG, DE91.216.245.193

Checks

  • ✓ 3 nameservers #6
    Delegated to ns1.werk21system.de, ns2.werk21system.de, ns3.werk21system.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 3 IPv4 /24s and 0 IPv6 /48s.
  • ✓ 3 autonomous systems #11
    The nameservers are spread over: AS203329 (ESHELTER - NTT Global Data Centers EMEA GmbH, DE): 1 address; AS24940 (HETZNER-AS - Hetzner Online GmbH, DE): 1 address; AS48314 (IP-PROJECTS - Michael Sebastian Schinzel trading as IP-Projects GmbH & Co. KG, DE): 1 address.
  • 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
  • !
    No IPv6
    None of the nameservers has an IPv6 address, so IPv6-only resolvers can't reach them.
    #13

Nameservers

info

3 of 3 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns1.werk21system.de 149.233.9.125NOERROR, 10 ms, authoritativenoyes / yesrefused9
ns2.werk21system.de 49.13.240.49NOERROR, 4 ms, authoritativenoyes / yesrefused9
ns3.werk21system.de 91.216.245.193NOERROR, 5 ms, authoritativenoyes / yesrefused9

Checks

  • ✓ All respond #14
    All 3 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: ns1.werk21system.de: "9"; ns2.werk21system.de: "9"; ns3.werk21system.de: "9".
    #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 2026051200 · primary ns.werk21system.de

Found

Primary (MNAME)
ns.werk21system.de
Contact (RNAME)
hostmaster.werk21.de
Serial
2026051200
Refresh / retry
86400 s / 900 s
Expire
2592000 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
ns1.werk21system.de (149.233.9.125)2026051200
ns2.werk21system.de (49.13.240.49)2026051200
ns3.werk21system.de (91.216.245.193)2026051200

Checks

  • ✓ Serial 2026051200 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 1d, retry 15m, expire 30d, negative TTL 1h.
  • i
    Hidden master
    The primary nameserver ns.werk21system.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 hostmaster@werk21.de #25
    The SOA RNAME hostmaster.werk21.de means hostmaster@werk21.de.
  • ✓ Date-based serial #26
    The serial 2026051200 follows the YYYYMMDDnn convention (2026-05-12).

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

8 records at the apex

Found

Read from
149.233.9.125:53
TypeValueTTL
SOAns.werk21system.de. hostmaster.werk21.de. 2026051200 86400 900 2592000 360010800
NSns3.werk21system.de.10800
NSns2.werk21system.de.10800
NSns1.werk21system.de.10800
A149.233.9.8610800
MX10 mx.essen.de.10800
TXT"brevo-code:0746b9500ab05d578d818d6e4d9c1fa9"10800
TXT"v=spf1 a mx include:spf1.werk21system.de include:essen.de ~all"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