zeiss.de

Checked 22 October 2026, 01:20 UTC · via 8.8.8.8
!Passed with warnings
21 passed 3 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

a1-232.akam.net, a13-66.akam.net, a18-66.akam.net, a26-67.akam.net, a7-64.akam.net, a8-64.akam.net

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
a1-232.akam.net, a13-66.akam.net, a18-66.akam.net, a26-67.akam.net, a7-64.akam.net, a8-64.akam.net
NS in the zone
a1-232.akam.net, a13-66.akam.net, a18-66.akam.net, a26-67.akam.net, a7-64.akam.net, a8-64.akam.net
NameserverAddressesNetwork (AS)Glue
a1-232.akam.net193.108.91.232 2600:1401:2::e8AS21342 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-
a18-66.akam.net95.101.36.66 2600:1480:4800::42AS21342 AKAMAI-ASN2 - Akamai International B.V., NL AS21342 AKAMAI-ASN2 - Akamai International B.V., NL-
a26-67.akam.net23.74.25.67 2600:1480:b800::43AS21342 AKAMAI-ASN2 - Akamai International B.V., NL AS21342 AKAMAI-ASN2 - Akamai International B.V., NL-
a7-64.akam.net23.61.199.64 2600:1406:32::40AS21342 AKAMAI-ASN2 - Akamai International B.V., NL AS21342 AKAMAI-ASN2 - Akamai International B.V., NL-
a8-64.akam.net2.16.40.64 2600:1403:a::40AS21342 AKAMAI-ASN2 - Akamai International B.V., NL AS21342 AKAMAI-ASN2 - Akamai International B.V., NL-

Checks

  • ✓ 6 nameservers #6
    Delegated to a1-232.akam.net, a13-66.akam.net, a18-66.akam.net, a26-67.akam.net, a7-64.akam.net, a8-64.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
a1-232.akam.net 193.108.91.232NOERROR, 5 ms, authoritativenoyes / yesrefused41824.6
a1-232.akam.net 2600:1401:2::e8NOERROR, 4 ms, authoritativenoyes / yesrefused41824.7
a13-66.akam.net 2.22.230.66NOERROR, 6 ms, authoritativenoyes / yesrefused41824.6
a13-66.akam.net 2600:1480:800::42NOERROR, 6 ms, authoritativenoyes / yesrefused41824.6
a18-66.akam.net 95.101.36.66NOERROR, 5 ms, authoritativenoyes / yesrefused48878.26
a18-66.akam.net 2600:1480:4800::42NOERROR, 6 ms, authoritativenoyes / yesrefused48878.30
a26-67.akam.net 23.74.25.67NOERROR, 5 ms, authoritativenoyes / yesrefused48878.30
a26-67.akam.net 2600:1480:b800::43NOERROR, 6 ms, authoritativenoyes / yesrefused48878.33
a7-64.akam.net 23.61.199.64NOERROR, 5 ms, authoritativenoyes / yesrefused41824.4
a7-64.akam.net 2600:1406:32::40NOERROR, 7 ms, authoritativenoyes / yesrefused41824.5
a8-64.akam.net 2.16.40.64NOERROR, 5 ms, authoritativenoyes / yesrefused48878.27
a8-64.akam.net 2600:1403:a::40NOERROR, 6 ms, authoritativenoyes / yesrefused48878.27

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: a1-232.akam.net: "41824.6"; a1-232.akam.net: "41824.7"; a13-66.akam.net: "41824.6"; a18-66.akam.net: "48878.26"; a18-66.akam.net: "48878.30"; a26-67.akam.net: "48878.30"; a26-67.akam.net: "48878.33"; a7-64.akam.net: "41824.4"; a7-64.akam.net: "41824.5"; a8-64.akam.net: "48878.27". 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 2018063064 · primary a1-232.akam.net

Found

Primary (MNAME)
a1-232.akam.net
Contact (RNAME)
hostmaster.zeiss.com
Serial
2018063064
Refresh / retry
10800 s / 3600 s
Expire
1209600 s
Negative TTL
900 s

Serial per nameserver

NameserverSerial
a1-232.akam.net (193.108.91.232)2018063064
a1-232.akam.net (2600:1401:2::e8)2018063064
a13-66.akam.net (2.22.230.66)2018063064
a13-66.akam.net (2600:1480:800::42)2018063064
a18-66.akam.net (95.101.36.66)2018063064
a18-66.akam.net (2600:1480:4800::42)2018063064
a26-67.akam.net (23.74.25.67)2018063064
a26-67.akam.net (2600:1480:b800::43)2018063064
a7-64.akam.net (23.61.199.64)2018063064
a7-64.akam.net (2600:1406:32::40)2018063064
a8-64.akam.net (2.16.40.64)2018063064
a8-64.akam.net (2600:1403:a::40)2018063064

Checks

  • ✓ Serial 2018063064 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 3h, retry 1h, expire 14d, negative TTL 15m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver a1-232.akam.net is one of the listed nameservers.
  • ✓ Contact hostmaster@zeiss.com #25
    The SOA RNAME hostmaster.zeiss.com means hostmaster@zeiss.com.
  • ✓ Date-based serial #26
    The serial 2018063064 follows the YYYYMMDDnn convention (2018-06-30).

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

15 records at the apex

Found

Read from
193.108.91.232:53
TypeValueTTL
SOAa1-232.akam.net. hostmaster.zeiss.com. 2018063064 10800 3600 1209600 9003600
NSa26-67.akam.net.3600
NSa7-64.akam.net.3600
NSa13-66.akam.net.3600
NSa8-64.akam.net.3600
NSa18-66.akam.net.3600
NSa1-232.akam.net.3600
A2.16.206.1820
A2.16.206.2520
AAAA2a02:26f0:b700:8::210:ce5120
AAAA2a02:26f0:b700:8::210:ce4420
MX10 mx-in02.eu.retarus.com.3600
MX10 mx-in01.eu.retarus.com.3600
TXT"google-site-verification=Bel_VwsZ9cwA0Pmdbb-QhM8V4865i0muRQe6KCqPk-c"3600
TXT"v=spf1 include:spf-mx.zeiss.com ip4:194.175.223.0/24 ip4:94.199.88.0/22 ip4:82.135.18.0/23 ip4:62.245.148.0/26 ip4:62.134.45.32/28 ip4:217.111.120.0/27 ip4:194.8.120.224/27 -all"3600

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 1h; 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