ostsee.de

Checked 21 October 2026, 23:42 UTC · via 8.8.8.8
!Passed with warnings
21 passed 3 warnings 0 failed 5 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

ns30.isuma.de, ns50.isuma.de, ns51.isuma.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
ns30.isuma.de, ns50.isuma.de, ns51.isuma.de
NS in the zone
ns30.isuma.de, ns50.isuma.de, ns51.isuma.de
NameserverAddressesNetwork (AS)Glue
ns30.isuma.de85.10.201.61AS24940 HETZNER-AS - Hetzner Online GmbH, DE85.10.201.61
ns50.isuma.de128.140.70.47AS24940 HETZNER-AS - Hetzner Online GmbH, DE128.140.70.47
ns51.isuma.de95.216.220.46AS24940 HETZNER-AS - Hetzner Online GmbH, DE95.216.220.46

Checks

  • ✓ 3 nameservers #6
    Delegated to ns30.isuma.de, ns50.isuma.de, ns51.isuma.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.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS24940 (HETZNER-AS - Hetzner Online GmbH, DE): 3 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
  • !
    No IPv6
    None of the nameservers has an IPv6 address, so IPv6-only resolvers can't reach them.
    #13

Nameservers

warn

3 of 3 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns30.isuma.de 85.10.201.61NOERROR, 0 ms, authoritativenoyes / yesrefusednone
ns50.isuma.de 128.140.70.47NOERROR, 2 ms, authoritativenoyes / yesrefused9.16.23-RH
ns51.isuma.de 95.216.220.46NOERROR, 29 ms, authoritativenoyes / yesrefused9.18.39-0ubuntu0.22.04.7-Ubuntu

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.
  • !
    Software version disclosed
    These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: ns50.isuma.de: "9.16.23-RH"; ns51.isuma.de: "9.18.39-0ubuntu0.22.04.7-Ubuntu". 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 2026091504 · primary ns30.isuma.de

Found

Primary (MNAME)
ns30.isuma.de
Contact (RNAME)
kontakt.isuma.de
Serial
2026091504
Refresh / retry
10800 s / 3600 s
Expire
604800 s
Negative TTL
10800 s

Serial per nameserver

NameserverSerial
ns30.isuma.de (85.10.201.61)2026091504
ns50.isuma.de (128.140.70.47)2026091504
ns51.isuma.de (95.216.220.46)2026091504

Checks

  • ✓ Serial 2026091504 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 3h, retry 1h, expire 7d, negative TTL 3h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns30.isuma.de is one of the listed nameservers.
  • ✓ Contact kontakt@isuma.de #25
    The SOA RNAME kontakt.isuma.de means kontakt@isuma.de.
  • ✓ Date-based serial #26
    The serial 2026091504 follows the YYYYMMDDnn convention (2026-09-15).

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

11 records at the apex

Found

Read from
85.10.201.61:53
TypeValueTTL
SOAns30.isuma.de. kontakt.isuma.de. 2026091504 10800 3600 604800 108003600
NSns30.isuma.de.3600
NSns50.isuma.de.3600
NSns51.isuma.de.3600
A78.47.30.1473600
MX0 ostsee-de.mail.protection.outlook.com.600
TXT"google-site-verification=_WREPHthjlFc3g9eUK1aJVk8NUzWF_JUdsT0lUw5Wk8"3600
TXT"facebook-domain-verification=ki76nrlogv0pgwlztg6qcae9ov52h7"3600
TXT"apple-domain-verification=vejn4kJe7xeMH2JqoRGxClsdyMjttnMsdA-yHRsz-78"3600
TXT"v=spf1 include:_spf30.isuma.de include:spf.protection.outlook.com ~all"3600
TXT"MS=ms43334023"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 1h, MX 10m, 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