helmholtz-berlin.de

Checked 21 October 2026, 22:50 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

info

dns-3.dfn.de, dns-w.helmholtz-berlin.de, dns.helmholtz-berlin.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-3.dfn.de, dns-w.helmholtz-berlin.de, dns.helmholtz-berlin.de
NS in the zone
dns-3.dfn.de, dns-w.helmholtz-berlin.de, dns.helmholtz-berlin.de
NameserverAddressesNetwork (AS)Glue
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-
dns-w.helmholtz-berlin.de134.30.95.132AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.30.95.132
dns.helmholtz-berlin.de193.149.11.132AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE193.149.11.132

Checks

  • ✓ 3 nameservers #6
    Delegated to dns-3.dfn.de, dns-w.helmholtz-berlin.de, dns.helmholtz-berlin.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: dns-w.helmholtz-berlin.de, dns.helmholtz-berlin.de.
  • ✓ 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 1 IPv6 /48.
  • 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): 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 .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: dns-w.helmholtz-berlin.de, dns.helmholtz-berlin.de.
    #13

Nameservers

warn

4 of 4 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
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
dns-w.helmholtz-berlin.de 134.30.95.132NOERROR, 18 ms, authoritativenoyes / yesrefused9.18.49-1~deb12u2-Debian
dns.helmholtz-berlin.de 193.149.11.132NOERROR, 13 ms, authoritativenoyes / yesrefused9.18.49-1~deb12u2-Debian

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.
  • !
    Software version disclosed
    These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: dns-w.helmholtz-berlin.de: "9.18.49-1~deb12u2-Debian"; dns.helmholtz-berlin.de: "9.18.49-1~deb12u2-Debian". 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 2026102100 · primary dns.helmholtz-berlin.de

Found

Primary (MNAME)
dns.helmholtz-berlin.de
Contact (RNAME)
dnsmaster.helmholtz-berlin.de
Serial
2026102100
Refresh / retry
14400 s / 1800 s
Expire
1209600 s
Negative TTL
43200 s

Serial per nameserver

NameserverSerial
dns-3.dfn.de (193.174.75.58)2026102100
dns-3.dfn.de (2001:638:d:b103::1)2026102100
dns-w.helmholtz-berlin.de (134.30.95.132)2026102100
dns.helmholtz-berlin.de (193.149.11.132)2026102100

Checks

  • ✓ Serial 2026102100 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 4h, retry 30m, expire 14d, negative TTL 12h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver dns.helmholtz-berlin.de is one of the listed nameservers.
  • ✓ Contact dnsmaster@helmholtz-berlin.de #25
    The SOA RNAME dnsmaster.helmholtz-berlin.de means dnsmaster@helmholtz-berlin.de.
  • ✓ Date-based serial #26
    The serial 2026102100 follows the YYYYMMDDnn convention (2026-10-21).

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

15 records at the apex

Found

Read from
193.174.75.58:53
TypeValueTTL
SOAdns.helmholtz-berlin.de. dnsmaster.helmholtz-berlin.de. 2026102100 14400 1800 1209600 4320014400
NSdns.helmholtz-berlin.de.14400
NSdns-3.dfn.de.14400
NSdns-w.helmholtz-berlin.de.14400
A134.30.15.14614400
MX10 b1391.mx.srv.dfn.de.14400
MX10 a1391.mx.srv.dfn.de.14400
MX10 c1391.mx.srv.dfn.de.14400
TXT"Helmholtz-Zentrum Berlin"3600
TXT"Hahn-Meitner-Platz 1"3600
TXT"cisco-ci-domain-verification=4c7fe339fd02798a111def11878ecdd6b8036848de693183b6dce52ba7b42e28"3600
TXT"14109 Berlin"3600
TXT"openai-domain-verification=dv-8EQmqslGvrjiKqMkT0XAuUfY"3600
TXT"MS=2EE2153337D71A025E16A6A7A0D3B2F8C78F8B6A"3600
TXT"v=spf1 ip4:134.30.18.147 ip4:134.30.18.148 include:spf.de.umantis.com include:spf.nl2go.com ~all"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 4h, MX 4h, NS 4h. The NS TTL at the parent is 1d and in the zone 4h; 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