offenbach.de

Checked 21 October 2026, 23:41 UTC · via 8.8.8.8
iAll checks passed
29 passed 0 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

anycast102.irondns.net, ns3.knipp.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
anycast102.irondns.net, ns3.knipp.de
NS in the zone
anycast102.irondns.net, ns3.knipp.de
NameserverAddressesNetwork (AS)Glue
anycast102.irondns.net195.253.88.5 2a01:5b0:10::5AS8561 KNIPPWORLDWIDE - Knipp Medien und Kommunikation GmbH, DE AS50611 KNIPP-IRONDNS1-AS - Knipp Medien und Kommunikation GmbH, DE-
ns3.knipp.de195.253.113.3 2a01:5b0:31::3AS8391 KNIPP-AS - Knipp Medien und Kommunikation GmbH, DE AS8391 KNIPP-AS - Knipp Medien und Kommunikation GmbH, DE-

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: anycast102.irondns.net, ns3.knipp.de.
    #6
  • ✓ 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 2 IPv4 /24s and 2 IPv6 /48s.
  • ✓ 3 autonomous systems #11
    The nameservers are spread over: AS50611 (KNIPP-IRONDNS1-AS - Knipp Medien und Kommunikation GmbH, DE): 1 address; AS8391 (KNIPP-AS - Knipp Medien und Kommunikation GmbH, DE): 2 addresses; AS8561 (KNIPPWORLDWIDE - Knipp Medien und Kommunikation GmbH, DE): 1 address.
  • ✓ Nameserver names under 2 TLDs #12
    Nameserver names use the TLDs .de, .net.
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

pass

4 of 4 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
anycast102.irondns.net 195.253.88.5NOERROR, 13 ms, authoritativenoyes / yesrefused-
anycast102.irondns.net 2a01:5b0:10::5NOERROR, 13 ms, authoritativenoyes / yesrefused-
ns3.knipp.de 195.253.113.3NOERROR, 10 ms, authoritativenoyes / yesrefused-
ns3.knipp.de 2a01:5b0:31::3NOERROR, 10 ms, authoritativenoyes / yesrefused-

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.
  • ✓ 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 2024042679 · primary ns3.knipp.de

Found

Primary (MNAME)
ns3.knipp.de
Contact (RNAME)
dnsmaster.irondns.net
Serial
2024042679
Refresh / retry
10800 s / 3000 s
Expire
2419200 s
Negative TTL
900 s

Serial per nameserver

NameserverSerial
anycast102.irondns.net (195.253.88.5)2024042679
anycast102.irondns.net (2a01:5b0:10::5)2024042679
ns3.knipp.de (195.253.113.3)2024042679
ns3.knipp.de (2a01:5b0:31::3)2024042679

Checks

  • ✓ Serial 2024042679 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 3h, retry 50m, expire 28d, negative TTL 15m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns3.knipp.de is one of the listed nameservers.
  • ✓ Contact dnsmaster@irondns.net #25
    The SOA RNAME dnsmaster.irondns.net means dnsmaster@irondns.net.
  • ✓ Date-based serial #26
    The serial 2024042679 follows the YYYYMMDDnn convention (2024-04-26).

DNSSEC

pass

Signed, DS published at parent

Found

Validated by resolver
yes
Denial of existence
NSEC3
NSEC3
0 iterations, 0-byte salt
Signatures valid until
2 November 2026

DS at the parent

Key tagAlgorithmDigestMatches a key
56394ECDSAP256SHA256 (13)SHA256 79E8F7A5E993D0C9…yes

DNSKEY in the zone

Key tagRoleAlgorithm
56394KSK (257)ECDSAP256SHA256 (13)
23990ZSK (256)ECDSAP256SHA256 (13)

Checks

  • ✓ Signed and validated #27
    The zone is signed, the parent publishes a DS record, and the resolver validates the answers.
  • ✓ DS matches a key #28
    The DS record at the parent matches a key in the zone: key tag 56394 (SHA256).
  • ✓ Modern algorithms #29
    Key algorithms: ECDSAP256SHA256 (13).
  • ✓ Signatures valid until 2026-11-02 #30
    The earliest DNSKEY/SOA signature expires at 2026-11-02 13:27 UTC.
  • ✓ NSEC3 as recommended #31
    The zone uses NSEC3 with 0 iterations and no salt (RFC 9276).

Records

info

10 records at the apex

Found

Read from
195.253.88.5:53
TypeValueTTL
SOAns3.knipp.de. dnsmaster.irondns.net. 2024042679 10800 3000 2419200 90086400
NSanycast102.irondns.net.86400
NSns3.knipp.de.86400
A104.151.107.134300
MX10 mailin.offenbach.de.3600
TXT"v=spf1 a ip4:24.40.191.66/32 ip4:104.151.107.129/32 a:ofmailout.offenbach.de a:ofmailgw02.offenbach.de a:ies.offenbach.de ip4:86.111.232.254/32 include:_spf1.ekom21.de ~all"600
TXT"google-site-verification=fC7rC7gTaBBihrzUlHB3U9EZqF1UgKbLHAt_oZSGBH4"600
TXT"google-site-verification=FBZr5WTNbkYs4vjcdQVBeBIiiIKsLGo105QstPhK36o"600
TXT"apple-domain-verification=pcd6QeSAZbIQ2iBh"600
TXT"cisco-ci-domain-verification=492094def6ec736931379e93c481646c3886cd5c7074004f6ca08c224a6f3988"600

Checks

  • ✓ TTLs within range #32
    TTLs: A 5m, MX 1h, NS 1d.
  • ✓ 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