aerztekammer-berlin.de

Checked 21 October 2026, 21:28 UTC · via 8.8.8.8
!Passed with warnings
20 passed 1 warning 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

info

ns0.de.clara.net, ns1.de.clara.net

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
ns0.de.clara.net, ns1.de.clara.net
NS in the zone
ns0.de.clara.net, ns1.de.clara.net
NameserverAddressesNetwork (AS)Glue
ns0.de.clara.net213.221.90.240 2a00:1798::1:53AS8426 CLARANET-AS - Claranet Limited, GB AS8426 CLARANET-AS - Claranet Limited, GB-
ns1.de.clara.net212.82.240.193 2a00:1798:0:400::1:53AS8426 CLARANET-AS - Claranet Limited, GB AS8426 CLARANET-AS - Claranet Limited, GB-

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: ns0.de.clara.net, ns1.de.clara.net.
    #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.
  • i
    One address family in one network
    all IPv6 addresses are in 2a00:1798::/48, while the other address family is spread over several networks.
    #10
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS8426 (CLARANET-AS - Claranet Limited, GB): 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 .net
    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
ns0.de.clara.net 213.221.90.240NOERROR, 3 ms, authoritativenoyes / yesrefusedClaraDNS / ixf-nscn01
ns0.de.clara.net 2a00:1798::1:53NOERROR, 3 ms, authoritativenoyes / yesrefusedClaraDNS / ixf-nscn01
ns1.de.clara.net 212.82.240.193NOERROR, 3 ms, authoritativenoyes / yesrefusedClaraDNS / ixf-nscn01
ns1.de.clara.net 2a00:1798:0:400::1:53NOERROR, 3 ms, authoritativenoyes / yesrefusedClaraDNS / ixf-nscn01

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: ns0.de.clara.net: "ClaraDNS / ixf-nscn01"; ns1.de.clara.net: "ClaraDNS / ixf-nscn01".
    #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 2025031301 · primary ns0.de.clara.net

Found

Primary (MNAME)
ns0.de.clara.net
Contact (RNAME)
hostmaster.de.clara.net
Serial
2025031301
Refresh / retry
28800 s / 3600 s
Expire
1209600 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
ns0.de.clara.net (213.221.90.240)2025031301
ns0.de.clara.net (2a00:1798::1:53)2025031301
ns1.de.clara.net (212.82.240.193)2025031301
ns1.de.clara.net (2a00:1798:0:400::1:53)2025031301

Checks

  • ✓ Serial 2025031301 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 8h, retry 1h, expire 14d, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns0.de.clara.net is one of the listed nameservers.
  • ✓ Contact hostmaster@de.clara.net #25
    The SOA RNAME hostmaster.de.clara.net means hostmaster@de.clara.net.
  • ✓ Date-based serial #26
    The serial 2025031301 follows the YYYYMMDDnn convention (2025-03-13).

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

4 records at the apex

Found

Read from
213.221.90.240:53
TypeValueTTL
SOAns0.de.clara.net. hostmaster.de.clara.net. 2025031301 28800 3600 1209600 8640086400
NSns0.de.clara.net.86400
NSns1.de.clara.net.86400
A167.233.10.11386400

Checks

  • ✓ TTLs within range #32
    TTLs: A 1d, NS 1d.
  • ✓ 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