studyflix.de

Checked 22 October 2026, 00:31 UTC · via 8.8.8.8
!Passed with warnings
22 passed 2 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

info

dns009.arvato-systems.de, dns017.arvato-systems.de, ns1.arvato-systems.de, ns2.arvato-systems.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns009.arvato-systems.de, dns017.arvato-systems.de, ns1.arvato-systems.de, ns2.arvato-systems.de
NS in the zone
dns009.arvato-systems.de, dns017.arvato-systems.de, ns1.arvato-systems.de, ns2.arvato-systems.de
NameserverAddressesNetwork (AS)Glue
dns009.arvato-systems.de193.189.249.157AS6805 TDDE-ASN1 - Telefonica Germany GmbH & Co.OHG, DE193.189.249.157
dns017.arvato-systems.de84.17.190.100AS33873 arvato-systems-AS - Arvato Systems GmbH, DE84.17.190.100
ns1.arvato-systems.de84.17.168.69 2a01:4a8:3222:2222::10AS33873 arvato-systems-AS - Arvato Systems GmbH, DE AS33873 arvato-systems-AS - Arvato Systems GmbH, DE84.17.168.69 2a01:4a8:3222:2222::10
ns2.arvato-systems.de109.235.143.148 2a01:4a8:2222:2222::11AS33873 arvato-systems-AS - Arvato Systems GmbH, DE AS33873 arvato-systems-AS - Arvato Systems GmbH, DE109.235.143.148 2a01:4a8:2222:2222::11

Checks

  • ✓ 4 nameservers #6
    Delegated to dns009.arvato-systems.de, dns017.arvato-systems.de, ns1.arvato-systems.de, ns2.arvato-systems.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 4 IPv4 /24s and 2 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS33873 (arvato-systems-AS - Arvato Systems GmbH, DE): 5 addresses; AS6805 (TDDE-ASN1 - Telefonica Germany GmbH & Co.OHG, DE): 1 address.
  • 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: dns009.arvato-systems.de, dns017.arvato-systems.de.
    #13

Nameservers

warn

6 of 6 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns009.arvato-systems.de 193.189.249.157NOERROR, 10 ms, authoritativenoyes / yesrefused42
dns017.arvato-systems.de 84.17.190.100NOERROR, 9 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.1.0 (built Nov 30 2017 10:13:06 by mockbuild@jenkins.monshouwer.eu)
ns1.arvato-systems.de 84.17.168.69NOERROR, 15 ms, authoritativenoyes / yesrefusedhttps://www.youtube.com/watch?v=7qnd-hdmgfk
ns1.arvato-systems.de 2a01:4a8:3222:2222::10NOERROR, 15 ms, authoritativenoyes / yesrefusedhttps://www.youtube.com/watch?v=7qnd-hdmgfk
ns2.arvato-systems.de 109.235.143.148NOERROR, 9 ms, authoritativenoyes / yesrefusedhttps://www.youtube.com/watch?v=7qnd-hdmgfk
ns2.arvato-systems.de 2a01:4a8:2222:2222::11NOERROR, 11 ms, authoritativenoyes / yesrefusedhttps://www.youtube.com/watch?v=7qnd-hdmgfk

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.
  • !
    Software version disclosed
    These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: dns017.arvato-systems.de: "PowerDNS Authoritative Server 4.1.0 (built Nov 30 2017 10:13:06 by mockbuild@jenkins.monshouwer.eu)". 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 2026092400 · primary dns009.arvato-systems.de

Found

Primary (MNAME)
dns009.arvato-systems.de
Contact (RNAME)
hostmaster.bnic.bertelsmann.de
Serial
2026092400
Refresh / retry
3600 s / 1800 s
Expire
3600000 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
dns009.arvato-systems.de (193.189.249.157)2026092400
dns017.arvato-systems.de (84.17.190.100)2026092400
ns1.arvato-systems.de (84.17.168.69)2026092400
ns1.arvato-systems.de (2a01:4a8:3222:2222::10)2026092400
ns2.arvato-systems.de (109.235.143.148)2026092400
ns2.arvato-systems.de (2a01:4a8:2222:2222::11)2026092400

Checks

  • ✓ Serial 2026092400 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 1h, retry 30m, expire 1000h, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver dns009.arvato-systems.de is one of the listed nameservers.
  • ✓ Contact hostmaster@bnic.bertelsmann.de #25
    The SOA RNAME hostmaster.bnic.bertelsmann.de means hostmaster@bnic.bertelsmann.de.
  • ✓ Date-based serial #26
    The serial 2026092400 follows the YYYYMMDDnn convention (2026-09-24).

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
193.189.249.157:53
TypeValueTTL
SOAdns009.arvato-systems.de. hostmaster.bnic.bertelsmann.de. 2026092400 3600 1800 3600000 36003600
NSns1.arvato-systems.de.3600
NSns2.arvato-systems.de.3600
NSdns009.arvato-systems.de.3600
NSdns017.arvato-systems.de.3600
A213.155.86.1463600
AAAA2001:780:205:0:213:155:86:1463600
MX10 studyflix-de.mail.protection.outlook.com.3600
TXT"MS=ms58886809"3600
TXT"MS=ms50731452"3600
TXT"v=spf1 include:_spf.makandra.de include:spf.sendinblue.com include:spf.protection.outlook.com include:spf.servicemail24.de include:servers.mcsv.net -all"3600
TXT"google-site-verification=S5YalED0CNYEvPM-j6Z5ImTuNCtcNBJztPdSughKi-c"3600
TXT"google-gws-recovery-domain-verification=73993585"3600
TXT"google-site-verification=5Pc6j1HqD7pL_drcAEATB-pp_MQxs30BYBszk5wd180"3600
TXT"apple-domain-verification=GtT1sppp0bbRLE8J"3600
TXT"google-site-verification=gtkMbTRXa-dmR6AZq78Jeo2qzBKkE4__ZaECD-tG4o0"3600
TXT"sipgate_domain_verification=jGgynKzoQZqKlzy9CDb3aLz7FmvPuHoo"3600

Checks

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