dsmz.de

Checked 21 October 2026, 22:15 UTC · via 8.8.8.8
!Passed with warnings
19 passed 2 warnings 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-1.dfn.de, dns-2.dfn.de, dns-3.dfn.de, ns1.dsmz.de, ns2.dsmz.de, ns3.dsmz.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-1.dfn.de, dns-2.dfn.de, dns-3.dfn.de, ns1.dsmz.de, ns2.dsmz.de, ns3.dsmz.de
NS in the zone
dns-1.dfn.de, dns-2.dfn.de, dns-3.dfn.de, ns1.dsmz.de, ns2.dsmz.de, ns3.dsmz.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-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-
ns1.dsmz.de194.94.219.2AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE194.94.219.2
ns2.dsmz.de194.94.219.3AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE194.94.219.3
ns3.dsmz.de194.94.219.4AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE194.94.219.4

Checks

  • ✓ 6 nameservers #6
    Delegated to dns-1.dfn.de, dns-2.dfn.de, dns-3.dfn.de, ns1.dsmz.de, ns2.dsmz.de, ns3.dsmz.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: ns1.dsmz.de, ns2.dsmz.de, ns3.dsmz.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): 9 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: ns1.dsmz.de, ns2.dsmz.de, ns3.dsmz.de.
    #13

Nameservers

info

9 of 9 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns-1.dfn.de 193.174.75.50NOERROR, 13 ms, authoritativenoyes / yesrefused0
dns-1.dfn.de 2001:638:d:b101::1NOERROR, 18 ms, authoritativenoyes / yesrefused0
dns-2.dfn.de 193.174.75.54NOERROR, 7 ms, authoritativenoyes / yesrefused0
dns-2.dfn.de 2001:638:d:b102::1NOERROR, 10 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 193.174.75.58NOERROR, 10 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 2001:638:d:b103::1NOERROR, 8 ms, authoritativenoyes / yesrefused0
ns1.dsmz.de 194.94.219.2NOERROR, 17 ms, authoritativenoyes / yesrefused-
ns2.dsmz.de 194.94.219.3NOERROR, 17 ms, authoritativenoyes / yesrefused-
ns3.dsmz.de 194.94.219.4NOERROR, 17 ms, authoritativenoyes / yesrefused-

Checks

  • ✓ All respond #14
    All 9 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-1.dfn.de: "0"; dns-2.dfn.de: "0"; dns-3.dfn.de: "0".
    #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

warn

serial 2026081000 · primary ns1.dsmz.de

Found

Primary (MNAME)
ns1.dsmz.de
Contact (RNAME)
dcn.dsmz.de
Serial
2026081000
Refresh / retry
900 s / 300 s
Expire
604800 s
Negative TTL
900 s

Serial per nameserver

NameserverSerial
dns-1.dfn.de (193.174.75.50)2026081000
dns-1.dfn.de (2001:638:d:b101::1)2026081000
dns-2.dfn.de (193.174.75.54)2026081000
dns-2.dfn.de (2001:638:d:b102::1)2026081000
dns-3.dfn.de (193.174.75.58)2026081000
dns-3.dfn.de (2001:638:d:b103::1)2026081000
ns1.dsmz.de (194.94.219.2)2026081000
ns2.dsmz.de (194.94.219.3)2026081000
ns3.dsmz.de (194.94.219.4)2026081000

Checks

  • ✓ Serial 2026081000 everywhere #22
    All nameservers serve the same version of the zone.
  • !
    Unusual SOA timers
    refresh 15m is outside 20m–1d. Current values: refresh 15m, retry 5m, expire 7d, negative TTL 15m.
    #23
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns1.dsmz.de is one of the listed nameservers.
  • ✓ Contact dcn@dsmz.de #25
    The SOA RNAME dcn.dsmz.de means dcn@dsmz.de.
  • ✓ Date-based serial #26
    The serial 2026081000 follows the YYYYMMDDnn convention (2026-08-10).

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

17 records at the apex

Found

Read from
193.174.75.50:53
TypeValueTTL
SOAns1.dsmz.de. dcn.dsmz.de. 2026081000 900 300 604800 900900
NSns3.dsmz.de.3600
NSns1.dsmz.de.3600
NSns2.dsmz.de.3600
NSdns-3.dfn.de.3600
NSdns-2.dfn.de.3600
NSdns-1.dfn.de.3600
A194.94.219.53600
MX10 c1641.mx.srv.dfn.de.600
MX10 a1641.mx.srv.dfn.de.600
MX10 b1641.mx.srv.dfn.de.600
TXT"apple-domain-verification=Wh8eCvuaasDGIbo1"3600
TXT"v=spf1 include:spf.mailsupport.dfn.de a:mail.dsmz.de a:mailserver.dsmz.de ~all"3600
TXT"MS=ms44280750"3600
TXT"HARICA-fgHfRBsk4lAR2P9EG48"3600
CAA0 issue "harica.gr"3600
CAA0 issue "pki.dfn.de"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.
  • i
    Wildcard record
    A random name under the zone resolves, so there is a wildcard (*) record. Typos and non-existent hosts resolve too, which can confuse mail and certificate checks.
    #34
  • ✓ CAA restricts issuance #35
    Certificates may be issued by: harica.gr, pki.dfn.de.