helios-kliniken.de

Checked 21 October 2026, 22:50 UTC · via 8.8.8.8
!Passed with warnings
22 passed 3 warnings 0 failed 4 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

a1-53.akam.net, a11-64.akam.net, a13-66.akam.net, a16-65.akam.net, a2-64.akam.net, a4-64.akam.net

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
a1-53.akam.net, a11-64.akam.net, a13-66.akam.net, a16-65.akam.net, a2-64.akam.net, a4-64.akam.net
NS in the zone
a1-53.akam.net, a11-64.akam.net, a13-66.akam.net, a16-65.akam.net, a2-64.akam.net, a4-64.akam.net
NameserverAddressesNetwork (AS)Glue
a1-53.akam.net193.108.91.53 2600:1401:2::35AS21342 AKAMAI-ASN2 - Akamai International B.V., NL AS21342 AKAMAI-ASN2 - Akamai International B.V., NL-
a11-64.akam.net84.53.139.64 2600:1480:1::40AS21342 AKAMAI-ASN2 - Akamai International B.V., NL AS21342 AKAMAI-ASN2 - Akamai International B.V., NL-
a13-66.akam.net2.22.230.66 2600:1480:800::42AS21342 AKAMAI-ASN2 - Akamai International B.V., NL AS21342 AKAMAI-ASN2 - Akamai International B.V., NL-
a16-65.akam.net23.211.132.65 2600:1406:1b::41AS21342 AKAMAI-ASN2 - Akamai International B.V., NL AS21342 AKAMAI-ASN2 - Akamai International B.V., NL-
a2-64.akam.net95.100.174.64 2600:1480:7000::40AS21342 AKAMAI-ASN2 - Akamai International B.V., NL AS21342 AKAMAI-ASN2 - Akamai International B.V., NL-
a4-64.akam.net72.246.46.64 2600:1480:9000::40AS21342 AKAMAI-ASN2 - Akamai International B.V., NL AS21342 AKAMAI-ASN2 - Akamai International B.V., NL-

Checks

  • ✓ 6 nameservers #6
    Delegated to a1-53.akam.net, a11-64.akam.net, a13-66.akam.net, a16-65.akam.net, a2-64.akam.net, a4-64.akam.net.
  • ✓ 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 6 IPv4 /24s and 6 IPv6 /48s.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS21342 (AKAMAI-ASN2 - Akamai International B.V., NL): 12 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

warn

12 of 12 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
a1-53.akam.net 193.108.91.53NOERROR, 3 ms, authoritativenoyes / yesrefused41824.8
a1-53.akam.net 2600:1401:2::35NOERROR, 3 ms, authoritativenoyes / yesrefused41824.8
a11-64.akam.net 84.53.139.64NOERROR, 3 ms, authoritativenoyes / yesrefused41824.11
a11-64.akam.net 2600:1480:1::40NOERROR, 3 ms, authoritativenoyes / yesrefused41824.5
a13-66.akam.net 2.22.230.66NOERROR, 4 ms, authoritativenoyes / yesrefused41824.9
a13-66.akam.net 2600:1480:800::42NOERROR, 4 ms, authoritativenoyes / yesrefused41824.5
a16-65.akam.net 23.211.132.65NOERROR, 3 ms, authoritativenoyes / yesrefused48878.26
a16-65.akam.net 2600:1406:1b::41NOERROR, 4 ms, authoritativenoyes / yesrefused48878.31
a2-64.akam.net 95.100.174.64NOERROR, 4 ms, authoritativenoyes / yesrefused48878.32
a2-64.akam.net 2600:1480:7000::40NOERROR, 3 ms, authoritativenoyes / yesrefused48878.33
a4-64.akam.net 72.246.46.64NOERROR, 3 ms, authoritativenoyes / yesrefused48878.32
a4-64.akam.net 2600:1480:9000::40NOERROR, 3 ms, authoritativenoyes / yesrefused48878.33

Checks

  • ✓ All respond #14
    All 12 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: a1-53.akam.net: "41824.8"; a11-64.akam.net: "41824.11"; a11-64.akam.net: "41824.5"; a13-66.akam.net: "41824.9"; a13-66.akam.net: "41824.5"; a16-65.akam.net: "48878.26"; a16-65.akam.net: "48878.31"; a2-64.akam.net: "48878.32"; a2-64.akam.net: "48878.33"; a4-64.akam.net: "48878.32"; a4-64.akam.net: "48878.33". 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 2023022876 · primary a1-53.akam.net

Found

Primary (MNAME)
a1-53.akam.net
Contact (RNAME)
hostmaster.helios-gesundheit.de
Serial
2023022876
Refresh / retry
28800 s / 7200 s
Expire
1209800 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
a1-53.akam.net (193.108.91.53)2023022876
a1-53.akam.net (2600:1401:2::35)2023022876
a11-64.akam.net (84.53.139.64)2023022876
a11-64.akam.net (2600:1480:1::40)2023022876
a13-66.akam.net (2.22.230.66)2023022876
a13-66.akam.net (2600:1480:800::42)2023022876
a16-65.akam.net (23.211.132.65)2023022876
a16-65.akam.net (2600:1406:1b::41)2023022876
a2-64.akam.net (95.100.174.64)2023022876
a2-64.akam.net (2600:1480:7000::40)2023022876
a4-64.akam.net (72.246.46.64)2023022876
a4-64.akam.net (2600:1480:9000::40)2023022876

Checks

  • ✓ Serial 2023022876 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 8h, retry 2h, expire 336h3m20s, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver a1-53.akam.net is one of the listed nameservers.
  • ✓ Contact hostmaster@helios-gesundheit.de #25
    The SOA RNAME hostmaster.helios-gesundheit.de means hostmaster@helios-gesundheit.de.
  • ✓ Date-based serial #26
    The serial 2023022876 follows the YYYYMMDDnn convention (2023-02-28).

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

warn

23 records at the apex

Found

Read from
193.108.91.53:53
TypeValueTTL
SOAa1-53.akam.net. hostmaster.helios-gesundheit.de. 2023022876 28800 7200 1209800 86400600
NSa13-66.akam.net.600
NSa2-64.akam.net.600
NSa11-64.akam.net.600
NSa1-53.akam.net.600
NSa16-65.akam.net.600
NSa4-64.akam.net.600
A2.16.204.9220
A2.16.204.8820
AAAA2a02:26f0:b700:5::210:cc0420
AAAA2a02:26f0:b700:5::210:cc1020
MX10 mx6.helios-kliniken.de.600
MX10 mx5.helios-kliniken.de.600
TXT"wxtBmDok6MaAQxSQinVhdeGOZVV3DkGcSe77tHslD1bI/jDJ7PNPuxTLi/97CQnSmGclHA6beXHJ/B47Riixig=="600
TXT"apple-domain-verification=IqnSb0tKtO6U3kWF"600
TXT"MS=ms18743103"600
TXT"_globalsign-domain-verification=3kXquqLttILGLKZqvHRcx-zx5zWePvJ3rT7i-a6hHJ"600
TXT"v=spf1 mx ip4:193.104.84.96/32 ip4:193.104.84.97/32 ip4:94.198.59.108/32 ip4:193.104.84.10/32 ip4:193.104.84.98/32 ip4:5.199.137.199/32 ip4:185.109.108.148/32 -all"600
TXT"rovag_verification_token=4EFE00D2BF614D6BB5E86E0C706CFA3C"600
CAA0 issue "globalsign.com"600
CAA0 issue "letsencrypt.org"600
CAA0 iodef "mailto:domainverwaltung@helios-gesundheit.de"600
CAA0 issuewild ";"600

Checks

  • !
    Very low TTLs
    These records have a TTL below 5m, causing extra queries and slower lookups: A (20s), AAAA (20s). Low TTLs are useful just before a planned change. The NS TTL at the parent is 1d and in the zone 10m; resolvers may use either.
    #32
  • ✓ No CNAME at the apex #33
    The zone apex has no CNAME record.
  • ✓ No wildcard #34
    Names that don't exist return NXDOMAIN.
  • ✓ CAA restricts issuance #35
    Certificates may be issued by: globalsign.com, letsencrypt.org, none (issuance forbidden).