uni-koblenz-landau.de

Checked 22 October 2026, 00:50 UTC · via 8.8.8.8
!Passed with warnings
19 passed 2 warnings 0 failed 8 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

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
ns3.uni-koblenz.de, ns4.uni-koblenz.de
NS in the zone
ns3.uni-koblenz.de, ns4.uni-koblenz.de
NameserverAddressesNetwork (AS)Glue
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

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: ns3.uni-koblenz.de, ns4.uni-koblenz.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.
  • i
    One address family in one network
    all IPv6 addresses are in 2001:4c80:50::/48, while the other address family is spread over several networks.
    #10
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS2857 (RLP-NET - Johannes Gutenberg-Universitaet Mainz, 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

warn

4 of 4 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
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, 6 ms, authoritativenoyes / yesrefused9.18.39-0ubuntu0.24.04.8-Ubuntu

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.
  • !
    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

info

serial 2017015624 · primary ns1.uni-koblenz.de

Found

Primary (MNAME)
ns1.uni-koblenz.de
Contact (RNAME)
hostmaster.uni-koblenz.de
Serial
2017015624
Refresh / retry
14400 s / 900 s
Expire
604800 s
Negative TTL
14400 s

Serial per nameserver

NameserverSerial
ns3.uni-koblenz.de (141.26.8.53)2017015624
ns3.uni-koblenz.de (2001:4c80:50::835)2017015624
ns4.uni-koblenz.de (141.26.9.53)2017015624
ns4.uni-koblenz.de (2001:4c80:50::935)2017015624

Checks

  • ✓ Serial 2017015624 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 4h, retry 15m, expire 7d, negative TTL 4h.
  • 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 2017015624 is a Unix timestamp (2033-12-01 02:07 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

7 records at the apex

Found

Read from
141.26.8.53:53
TypeValueTTL
SOAns1.uni-koblenz.de. hostmaster.uni-koblenz.de. 2017015624 14400 900 604800 1440014400
NSns4.uni-koblenz.de.14400
NSns3.uni-koblenz.de.14400
A141.26.65.93300
MX0 .300
TXT"google-site-verification=HJaAEXqPReHeXA5U8ceClB7glHrS83dkSkgXznGprVA"172801
TXT"v=spf1 mx ip4:141.26.64.8/32 ip4:141.26.64.10/32 ip4:141.26.64.14/32 ip4:141.26.64.15/32 ip4:141.26.64.19/32 ip4:141.26.220.2/32 ?all"172801

Checks

  • ✓ TTLs within range #32
    TTLs: A 5m, MX 5m, NS 4h. The NS TTL at the parent is 1d and in the zone 4h; 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