io-warnemuende.de

Checked 21 October 2026, 23:00 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

dns-2.dfn.de, dns-3.dfn.de, hiddensee.io-warnemuende.de, koos.io-warnemuende.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-2.dfn.de, dns-3.dfn.de, hiddensee.io-warnemuende.de, koos.io-warnemuende.de
NS in the zone
dns-2.dfn.de, dns-3.dfn.de, hiddensee.io-warnemuende.de, koos.io-warnemuende.de
NameserverAddressesNetwork (AS)Glue
dns-2.dfn.de193.174.75.54 2001:638:d:b102::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-
hiddensee.io-warnemuende.de192.124.245.11AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE192.124.245.11
koos.io-warnemuende.de192.124.245.9AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE192.124.245.9

Checks

  • ✓ 4 nameservers #6
    Delegated to dns-2.dfn.de, dns-3.dfn.de, hiddensee.io-warnemuende.de, koos.io-warnemuende.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: hiddensee.io-warnemuende.de, koos.io-warnemuende.de.
  • ✓ 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 2001:638:d::/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 (AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE): 6 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: hiddensee.io-warnemuende.de, koos.io-warnemuende.de.
    #13

Nameservers

info

6 of 6 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns-2.dfn.de 193.174.75.54NOERROR, 7 ms, authoritativenoyes / yesrefused0
dns-2.dfn.de 2001:638:d:b102::1NOERROR, 7 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 193.174.75.58NOERROR, 8 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 2001:638:d:b103::1NOERROR, 11 ms, authoritativenoyes / yesrefused0
hiddensee.io-warnemuende.de 192.124.245.11NOERROR, 20 ms, authoritativenoyes / yesrefusedNo version !
koos.io-warnemuende.de 192.124.245.9NOERROR, 20 ms, authoritativenoyes / yesrefusedNo version !

Checks

  • ✓ All respond #14
    All 6 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: dns-2.dfn.de: "0"; dns-3.dfn.de: "0"; hiddensee.io-warnemuende.de: "No version !"; koos.io-warnemuende.de: "No version !".
    #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 2026052801 · primary hiddensee.io-warnemuende.de

Found

Primary (MNAME)
hiddensee.io-warnemuende.de
Contact (RNAME)
root.hiddensee.io-warnemuende.de
Serial
2026052801
Refresh / retry
14400 s / 3600 s
Expire
1209600 s
Negative TTL
10800 s

Serial per nameserver

NameserverSerial
dns-2.dfn.de (193.174.75.54)2026052801
dns-2.dfn.de (2001:638:d:b102::1)2026052801
dns-3.dfn.de (193.174.75.58)2026052801
dns-3.dfn.de (2001:638:d:b103::1)2026052801
hiddensee.io-warnemuende.de (192.124.245.11)2026052801
koos.io-warnemuende.de (192.124.245.9)2026052801

Checks

  • ✓ Serial 2026052801 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 4h, retry 1h, expire 14d, negative TTL 3h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver hiddensee.io-warnemuende.de is one of the listed nameservers.
  • ✓ Contact root@hiddensee.io-warnemuende.de #25
    The SOA RNAME root.hiddensee.io-warnemuende.de means root@hiddensee.io-warnemuende.de.
  • ✓ Date-based serial #26
    The serial 2026052801 follows the YYYYMMDDnn convention (2026-05-28).

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
193.174.75.54:53
TypeValueTTL
SOAhiddensee.io-warnemuende.de. root.hiddensee.io-warnemuende.de. 2026052801 14400 3600 1209600 108003600
NSdns-2.dfn.de.10800
NSkoos.io-warnemuende.de.10800
NShiddensee.io-warnemuende.de.10800
NSdns-3.dfn.de.10800
A192.124.245.210800
MX10 hiddensee.io-warnemuende.de.10800
MX10 koos.io-warnemuende.de.10800
TXT"apple-domain-verification=4e3OokyLSKpFxUBJ"10800
TXT"MS=0F2581332D69F361296F486B2AA1EC5C2558FC7B"10800
TXT"v=spf1 ip4:192.124.245.147 ip4:192.124.245.151 ip4:192.124.245.150 ip4:192.124.245.9 ip4:192.124.245.11 ip4:192.124.245.154 a mx ~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