studysmarter.de

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

ns-1220.awsdns-24.org, ns-1595.awsdns-07.co.uk, ns-398.awsdns-49.com, ns-564.awsdns-06.net

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
ns-1220.awsdns-24.org, ns-1595.awsdns-07.co.uk, ns-398.awsdns-49.com, ns-564.awsdns-06.net
NS in the zone
ns-1220.awsdns-24.org, ns-1595.awsdns-07.co.uk, ns-398.awsdns-49.com, ns-564.awsdns-06.net
NameserverAddressesNetwork (AS)Glue
ns-1220.awsdns-24.org205.251.196.196 2600:9000:5304:c400::1AS16509 AMAZON-02 - Amazon.com, Inc., US AS16509 AMAZON-02 - Amazon.com, Inc., US-
ns-1595.awsdns-07.co.uk205.251.198.59 2600:9000:5306:3b00::1AS16509 AMAZON-02 - Amazon.com, Inc., US AS16509 AMAZON-02 - Amazon.com, Inc., US-
ns-398.awsdns-49.com205.251.193.142 2600:9000:5301:8e00::1AS16509 AMAZON-02 - Amazon.com, Inc., US AS16509 AMAZON-02 - Amazon.com, Inc., US-
ns-564.awsdns-06.net205.251.194.52 2600:9000:5302:3400::1AS16509 AMAZON-02 - Amazon.com, Inc., US AS16509 AMAZON-02 - Amazon.com, Inc., US-

Checks

  • ✓ 4 nameservers #6
    Delegated to ns-1220.awsdns-24.org, ns-1595.awsdns-07.co.uk, ns-398.awsdns-49.com, ns-564.awsdns-06.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 4 IPv4 /24s and 4 IPv6 /48s.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS16509 (AMAZON-02 - Amazon.com, Inc., US): 8 addresses). An outage or attack on that network affects all nameservers; large anycast providers mitigate this, but a secondary DNS provider adds independence.
    #11
  • ✓ Nameserver names under 4 TLDs #12
    Nameserver names use the TLDs .com, .net, .org, .uk.
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

pass

8 of 8 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns-1220.awsdns-24.org 205.251.196.196NOERROR, 4 ms, authoritativenoyes / yesrefused-
ns-1220.awsdns-24.org 2600:9000:5304:c400::1NOERROR, 4 ms, authoritativenoyes / yesrefused-
ns-1595.awsdns-07.co.uk 205.251.198.59NOERROR, 9 ms, authoritativenoyes / yesrefused-
ns-1595.awsdns-07.co.uk 2600:9000:5306:3b00::1NOERROR, 9 ms, authoritativenoyes / yesrefused-
ns-398.awsdns-49.com 205.251.193.142NOERROR, 10 ms, authoritativenoyes / yesrefused-
ns-398.awsdns-49.com 2600:9000:5301:8e00::1NOERROR, 9 ms, authoritativenoyes / yesrefused-
ns-564.awsdns-06.net 205.251.194.52NOERROR, 4 ms, authoritativenoyes / yesrefused-
ns-564.awsdns-06.net 2600:9000:5302:3400::1NOERROR, 7 ms, authoritativenoyes / yesrefused-

Checks

  • ✓ All respond #14
    All 8 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.
  • ✓ No version disclosed #17
    The nameservers don't reveal their software version.
  • ✓ 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 1 · primary ns-1220.awsdns-24.org

Found

Primary (MNAME)
ns-1220.awsdns-24.org
Contact (RNAME)
awsdns-hostmaster.amazon.com
Serial
1
Refresh / retry
7200 s / 900 s
Expire
1209600 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
ns-1220.awsdns-24.org (205.251.196.196)1
ns-1220.awsdns-24.org (2600:9000:5304:c400::1)1
ns-1595.awsdns-07.co.uk (205.251.198.59)1
ns-1595.awsdns-07.co.uk (2600:9000:5306:3b00::1)1
ns-398.awsdns-49.com (205.251.193.142)1
ns-398.awsdns-49.com (2600:9000:5301:8e00::1)1
ns-564.awsdns-06.net (205.251.194.52)1
ns-564.awsdns-06.net (2600:9000:5302:3400::1)1

Checks

  • ✓ Serial 1 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 2h, retry 15m, expire 14d, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns-1220.awsdns-24.org is one of the listed nameservers.
  • ✓ Contact awsdns-hostmaster@amazon.com #25
    The SOA RNAME awsdns-hostmaster.amazon.com means awsdns-hostmaster@amazon.com.
  • ✓ Counter serial #26
    The serial 1 is a plain counter.

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

20 records at the apex

Found

Read from
205.251.196.196:53
TypeValueTTL
SOAns-1220.awsdns-24.org. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400900
NSns-1220.awsdns-24.org.172800
NSns-1595.awsdns-07.co.uk.172800
NSns-398.awsdns-49.com.172800
NSns-564.awsdns-06.net.172800
A52.28.27.8260
A3.77.158.6360
A3.68.56.6460
MX1 aspmx.l.google.com.14400
MX10 alt3.aspmx.l.google.com.14400
MX10 alt4.aspmx.l.google.com.14400
MX5 alt1.aspmx.l.google.com.14400
MX5 alt2.aspmx.l.google.com.14400
TXT"MS=3F4B5344525FD843B8AF910D280AF308D9FC9C1A"300
TXT"detectify-verification=d8aa8923ee3948a69ca0ac304502489e"300
TXT"google-site-verification=khRwzQcgj3HuXJZUh9XvHXq_d8rA9wbHStL2MmQzX8Q"300
TXT"google-site-verification=mpMjtFqol1zTgIa8y8JR63xfihJId28TI3GnsBIq9Ek"300
TXT"google-site-verification=rXBh6MIyrCY8J8Uq_Xd_AA1NpryQkBaPk5G8dtSpuKQ"300
TXT"stripe-verification=6264a46b80a8dadd160716d09d034547ceb3f2cb5831760dc3e41d22c66986b8"300
TXT"v=spf1 a include:_spf.google.com include:sendgrid.net include:mail.zendesk.com ~all"300

Checks

  • !
    Very low TTLs
    These records have a TTL below 5m, causing extra queries and slower lookups: A (1m). Low TTLs are useful just before a planned change. The NS TTL at the parent is 1d and in the zone 2d; 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.
  • 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