visitessen.de

Checked 22 October 2026, 00:52 UTC · via 8.8.8.8
✗Problems found
20 passed 2 warnings 1 failed 6 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

eshdns01.essen.de, eshdns02.essen.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
eshdns01.essen.de, eshdns02.essen.de
NS in the zone
eshdns01.essen.de, eshdns02.essen.de
NameserverAddressesNetwork (AS)Glue
eshdns01.essen.de185.150.48.18 2a0b:a5c0:1:20:2::AS205807 ESH - Essener Systemhaus, DE AS205807 ESH - Essener Systemhaus, DE185.150.48.18 2a0b:a5c0:1:20:2::
eshdns02.essen.de185.150.50.2 2a0b:a5c4:1:20:2::AS205807 ESH - Essener Systemhaus, DE AS205807 ESH - Essener Systemhaus, DE185.150.50.2 2a0b:a5c4:1:20:2::

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: eshdns01.essen.de, eshdns02.essen.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.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS205807 (ESH - Essener Systemhaus, DE): 4 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 .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
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

fail

2 of 4 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
eshdns01.essen.de 185.150.48.18NOERROR, 14 ms, authoritativenoyes / yesrefused9.20.29-1~deb13u1+ubuntu24.04.1+deb.sury.org+1-Ubuntu
eshdns01.essen.de 2a0b:a5c0:1:20:2::no responsenono / no--
eshdns02.essen.de 185.150.50.2NOERROR, 10 ms, authoritativenoyes / yesrefused9.20.29-1~deb13u1+ubuntu24.04.1+deb.sury.org+1-Ubuntu
eshdns02.essen.de 2a0b:a5c4:1:20:2::no responsenono / no--

Checks

  • ✗
    Nameservers not responding
    These addresses did not answer, so resolvers waste time on timeouts: eshdns01.essen.de (2a0b:a5c0:1:20:2::): read udp [2a01:4f8:1c1c:eebf::1]:43398->[2a0b:a5c0:1:20:2::]:53: i/o timeout; eshdns02.essen.de (2a0b:a5c4:1:20:2::): read udp [2a01:4f8:1c1c:eebf::1]:51021->[2a0b:a5c4:1:20:2::]:53: i/o timeout.
    #14
  • ✓ 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: eshdns01.essen.de: "9.20.29-1~deb13u1+ubuntu24.04.1+deb.sury.org+1-Ubuntu"; eshdns02.essen.de: "9.20.29-1~deb13u1+ubuntu24.04.1+deb.sury.org+1-Ubuntu". 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 2026072701 · primary eshdns01.essen.de

Found

Primary (MNAME)
eshdns01.essen.de
Contact (RNAME)
eshfirewall.esh.essen.de
Serial
2026072701
Refresh / retry
10800 s / 3600 s
Expire
604800 s
Negative TTL
38400 s

Serial per nameserver

NameserverSerial
eshdns01.essen.de (185.150.48.18)2026072701
eshdns02.essen.de (185.150.50.2)2026072701

Checks

  • ✓ Serial 2026072701 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 3h, retry 1h, expire 7d, negative TTL 640m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver eshdns01.essen.de is one of the listed nameservers.
  • ✓ Contact eshfirewall@esh.essen.de #25
    The SOA RNAME eshfirewall.esh.essen.de means eshfirewall@esh.essen.de.
  • ✓ Date-based serial #26
    The serial 2026072701 follows the YYYYMMDDnn convention (2026-07-27).

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

4 records at the apex

Found

Read from
185.150.48.18:53
TypeValueTTL
SOAeshdns01.essen.de. eshfirewall.esh.essen.de. 2026072701 10800 3600 604800 3840038400
NSeshdns01.essen.de.38400
NSeshdns02.essen.de.38400
A185.150.51.2638400

Checks

  • ✓ TTLs within range #32
    TTLs: A 640m, NS 640m. The NS TTL at the parent is 1d and in the zone 640m; 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