uni-koblenz.de

Checked 22 October 2026, 00:50 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

ns1.hosting.de, ns3.uni-koblenz.de, ns4.uni-koblenz.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
ns1.hosting.de, ns3.uni-koblenz.de, ns4.uni-koblenz.de
NS in the zone
ns1.hosting.de, ns3.uni-koblenz.de, ns4.uni-koblenz.de
NameserverAddressesNetwork (AS)Glue
ns1.hosting.de134.0.30.178 2a03:2900:3:1::2AS48823 AS48823 - Hosting.de GmbH, DE AS48823 AS48823 - Hosting.de GmbH, DE134.0.30.178 2a03:2900:3:1::2
ns3.uni-koblenz.de141.26.8.53 2001:4c80:50::835AS2857 RLP-NET - Johannes Gutenberg-Universitaet Mainz, DE AS2857 RLP-NET - Johannes Gutenberg-Universitaet Mainz, DE141.26.8.53 2001:4c80:50::835
ns4.uni-koblenz.de141.26.9.53 2001:4c80:50::935AS2857 RLP-NET - Johannes Gutenberg-Universitaet Mainz, DE AS2857 RLP-NET - Johannes Gutenberg-Universitaet Mainz, DE141.26.9.53 2001:4c80:50::935

Checks

  • ✓ 3 nameservers #6
    Delegated to ns1.hosting.de, ns3.uni-koblenz.de, ns4.uni-koblenz.de.
  • ✓ Parent and zone agree #7
    The parent delegation and the zone's NS records list the same nameservers.
  • ✓ Glue present and correct #8
    Glue is published for the nameservers inside the zone: ns3.uni-koblenz.de, ns4.uni-koblenz.de.
  • ✓ 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 2 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS2857 (RLP-NET - Johannes Gutenberg-Universitaet Mainz, DE): 4 addresses; AS48823 (AS48823 - Hosting.de GmbH, DE): 2 addresses.
  • 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

warn

6 of 6 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns1.hosting.de 134.0.30.178NOERROR, 10 ms, authoritativenoyes / yesrefused-
ns1.hosting.de 2a03:2900:3:1::2NOERROR, 10 ms, authoritativenoyes / yesrefused-
ns3.uni-koblenz.de 141.26.8.53NOERROR, 5 ms, authoritativenoyes / yesrefused9.18.39-0ubuntu0.24.04.8-Ubuntu
ns3.uni-koblenz.de 2001:4c80:50::835NOERROR, 5 ms, authoritativenoyes / yesrefused9.18.39-0ubuntu0.24.04.8-Ubuntu
ns4.uni-koblenz.de 141.26.9.53NOERROR, 5 ms, authoritativenoyes / yesrefused9.18.39-0ubuntu0.24.04.8-Ubuntu
ns4.uni-koblenz.de 2001:4c80:50::935NOERROR, 5 ms, authoritativenoyes / yesrefused9.18.39-0ubuntu0.24.04.8-Ubuntu

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.
  • !
    Software version disclosed
    These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: ns3.uni-koblenz.de: "9.18.39-0ubuntu0.24.04.8-Ubuntu"; ns4.uni-koblenz.de: "9.18.39-0ubuntu0.24.04.8-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

warn

serial 2016454013 · primary ns1.uni-koblenz.de

Found

Primary (MNAME)
ns1.uni-koblenz.de
Contact (RNAME)
hostmaster.uni-koblenz.de
Serial
2016454013
Refresh / retry
14400 s / 900 s
Expire
172800 s
Negative TTL
300 s

Serial per nameserver

NameserverSerial
ns1.hosting.de (134.0.30.178)2016454013
ns1.hosting.de (2a03:2900:3:1::2)2016454013
ns3.uni-koblenz.de (141.26.8.53)2016454013
ns3.uni-koblenz.de (2001:4c80:50::835)2016454013
ns4.uni-koblenz.de (141.26.9.53)2016454013
ns4.uni-koblenz.de (2001:4c80:50::935)2016454013

Checks

  • ✓ Serial 2016454013 everywhere #22
    All nameservers serve the same version of the zone.
  • !
    Unusual SOA timers
    expire 2d is shorter than 7d; secondaries stop answering too soon when the primary is down. Current values: refresh 4h, retry 15m, expire 2d, negative TTL 5m.
    #23
  • i
    Hidden master
    The primary nameserver ns1.uni-koblenz.de is not listed as a nameserver: a hidden master that only feeds the public secondaries. That is a common setup; make sure it is not reachable for zone transfers from outside.
    #24
  • ✓ Contact hostmaster@uni-koblenz.de #25
    The SOA RNAME hostmaster.uni-koblenz.de means hostmaster@uni-koblenz.de.
  • ✓ Timestamp serial #26
    The serial 2016454013 is a Unix timestamp (2033-11-24 14:06 UTC).

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

12 records at the apex

Found

Read from
134.0.30.178:53
TypeValueTTL
SOAns1.uni-koblenz.de. hostmaster.uni-koblenz.de. 2016454013 14400 900 172800 300300
NSns3.uni-koblenz.de.300
NSns4.uni-koblenz.de.300
NSns1.hosting.de.300
A141.26.8.8300
AAAA2001:4c80:50::808300
MX5 mx.uni-koblenz.de.300
TXT"google-site-verification=-NzmO1Ng5iBmd1fZQAGXMl0NgtIkCSrbGbuhzsv7F1s"300
TXT"google-site-verification=vFBT5KbMvln7vs39Ly7EOladgpvvM2sfK_F2tcOz0mM"300
TXT"adobe-idp-site-verification=710a406d97692e09a32ba298742d69982b85a7b69c71209fa11d0d099e2a64f4"300
TXT"v=spf1 mx include:spf.uni-koblenz.de include:spf-eu.exlibrisgroup.com -all"300
TXT"MS=8A1FD6D9D2710623BCB91B020262CCE23A7A4FF9"300

Checks

  • ✓ TTLs within range #32
    TTLs: A 5m, AAAA 5m, MX 5m, NS 5m. The NS TTL at the parent is 1d and in the zone 5m; 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