zu.de

Checked 22 October 2026, 01:20 UTC · via 8.8.8.8
!Passed with warnings
24 passed 1 warning 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

cns1.alfahosting.info, cns2.alfahosting.info, cns3.alfahosting.info

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
cns1.alfahosting.info, cns2.alfahosting.info, cns3.alfahosting.info
NS in the zone
cns1.alfahosting.info, cns2.alfahosting.info, cns3.alfahosting.info
NameserverAddressesNetwork (AS)Glue
cns1.alfahosting.info109.237.142.8 2a01:64c0:0:5000::8AS45012 CLOUDPIT - dogado GmbH, DE AS45012 CLOUDPIT - dogado GmbH, DE-
cns2.alfahosting.info148.251.254.105 2a01:4f8:2b02:a88::105AS24940 HETZNER-AS - Hetzner Online GmbH, DE AS24940 HETZNER-AS - Hetzner Online GmbH, DE-
cns3.alfahosting.info109.237.143.8 2a02:2b80:101:5000::8AS45012 CLOUDPIT - dogado GmbH, DE AS45012 CLOUDPIT - dogado GmbH, DE-

Checks

  • ✓ 3 nameservers #6
    Delegated to cns1.alfahosting.info, cns2.alfahosting.info, cns3.alfahosting.info.
  • ✓ 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 3 IPv4 /24s and 3 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS24940 (HETZNER-AS - Hetzner Online GmbH, DE): 2 addresses; AS45012 (CLOUDPIT - dogado GmbH, DE): 4 addresses.
  • i
    All nameserver names under .info
    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

pass

6 of 6 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
cns1.alfahosting.info 109.237.142.8NOERROR, 16 ms, authoritativenoyes / yesrefused-
cns1.alfahosting.info 2a01:64c0:0:5000::8NOERROR, 16 ms, authoritativenoyes / yesrefused-
cns2.alfahosting.info 148.251.254.105NOERROR, 3 ms, authoritativenoyes / yesrefused-
cns2.alfahosting.info 2a01:4f8:2b02:a88::105NOERROR, 3 ms, authoritativenoyes / yesrefused-
cns3.alfahosting.info 109.237.143.8NOERROR, 16 ms, authoritativenoyes / yesrefused-
cns3.alfahosting.info 2a02:2b80:101:5000::8NOERROR, 16 ms, authoritativenoyes / yesrefused-

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.
  • ✓ 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 2026081907 · primary cns1.alfahosting.info

Found

Primary (MNAME)
cns1.alfahosting.info
Contact (RNAME)
hostmaster.alfahosting.de
Serial
2026081907
Refresh / retry
28800 s / 7200 s
Expire
604800 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
cns1.alfahosting.info (109.237.142.8)2026081907
cns1.alfahosting.info (2a01:64c0:0:5000::8)2026081907
cns2.alfahosting.info (148.251.254.105)2026081907
cns2.alfahosting.info (2a01:4f8:2b02:a88::105)2026081907
cns3.alfahosting.info (109.237.143.8)2026081907
cns3.alfahosting.info (2a02:2b80:101:5000::8)2026081907

Checks

  • ✓ Serial 2026081907 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 8h, retry 2h, expire 7d, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver cns1.alfahosting.info is one of the listed nameservers.
  • ✓ Contact hostmaster@alfahosting.de #25
    The SOA RNAME hostmaster.alfahosting.de means hostmaster@alfahosting.de.
  • ✓ Date-based serial #26
    The serial 2026081907 follows the YYYYMMDDnn convention (2026-08-19).

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

10 records at the apex

Found

Read from
109.237.142.8:53
TypeValueTTL
SOAcns1.alfahosting.info. hostmaster.alfahosting.de. 2026081907 28800 7200 604800 36003600
NScns1.alfahosting.info.3600
NScns2.alfahosting.info.3600
NScns3.alfahosting.info.3600
A85.13.136.1283600
MX0 d334026.b.ess.de.barracudanetworks.com.3600
MX0 d334026.a.ess.de.barracudanetworks.com.3600
TXT"jYw4p8NNjywh8Fgb5G3R8++Tuyp8+iuZYrslQ/ry9A3ofzCoM+02v2T7gXA4n4zJPYH5jWgwXx3FJ7SY6Nl++A=="3600
TXT"v=spf1 ip4:193.175.6.55 include:spf.protection.outlook.com include:spf.ess.de.barracudanetworks.com include:mail.zendesk.com include:_spf.createsend.com a:vereinonline.org include:_spf.salesforce.com include:_spf.tivian.com include:_spf.uni-freiburg.de -a" "ll"3600
TXT"g6Kq3Gqocv6hwLiszklHL1EsDT+U0yBEhEs+f1/zQ6Iw7gcm12ImDnDKsI7dgzZGyGvz3Tt7lVmxcEqO1NBmFw=="3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 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