hbz-nrw.de

Checked 21 October 2026, 22:42 UTC · via 8.8.8.8
!Passed with warnings
22 passed 2 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

dns1.uni-koeln.de, nse03.hbz-nrw.de, nse04.hbz-nrw.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns1.uni-koeln.de, nse03.hbz-nrw.de, nse04.hbz-nrw.de
NS in the zone
dns1.uni-koeln.de, nse03.hbz-nrw.de, nse04.hbz-nrw.de
NameserverAddressesNetwork (AS)Glue
dns1.uni-koeln.de134.95.44.35 2a00:a200:0:56::53AS5520 UNI-KOELN - Universitaet zu Koeln, DE AS5520 UNI-KOELN - Universitaet zu Koeln, DE-
nse03.hbz-nrw.de193.30.112.3AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE193.30.112.3
nse04.hbz-nrw.de193.30.112.4AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE193.30.112.4

Checks

  • ✓ 3 nameservers #6
    Delegated to dns1.uni-koeln.de, nse03.hbz-nrw.de, nse04.hbz-nrw.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: nse03.hbz-nrw.de, nse04.hbz-nrw.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 2 IPv4 /24s and 1 IPv6 /48.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS5520 (UNI-KOELN - Universitaet zu Koeln, DE): 2 addresses; AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., 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
  • i
    Partly IPv6
    These nameservers have no IPv6 address: nse03.hbz-nrw.de, nse04.hbz-nrw.de.
    #13

Nameservers

warn

4 of 4 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns1.uni-koeln.de 134.95.44.35NOERROR, 11 ms, authoritativenoyes / yesrefused-
dns1.uni-koeln.de 2a00:a200:0:56::53NOERROR, 11 ms, authoritativenoyes / yesrefused-
nse03.hbz-nrw.de 193.30.112.3NOERROR, 19 ms, authoritativenoyes / yesrefused9.20.29
nse04.hbz-nrw.de 193.30.112.4NOERROR, 19 ms, authoritativenoyes / yesrefused9.20.29

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: nse03.hbz-nrw.de: "9.20.29"; nse04.hbz-nrw.de: "9.20.29". 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 2026102100 · primary ns00.hbz-nrw.de

Found

Primary (MNAME)
ns00.hbz-nrw.de
Contact (RNAME)
unix.hbz-nrw.de
Serial
2026102100
Refresh / retry
7200 s / 2400 s
Expire
3600000 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
dns1.uni-koeln.de (134.95.44.35)2026102100
dns1.uni-koeln.de (2a00:a200:0:56::53)2026102100
nse03.hbz-nrw.de (193.30.112.3)2026102100
nse04.hbz-nrw.de (193.30.112.4)2026102100

Checks

  • ✓ Serial 2026102100 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 2h, retry 40m, expire 1000h, negative TTL 1h.
  • i
    Hidden master
    The primary nameserver ns00.hbz-nrw.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 unix@hbz-nrw.de #25
    The SOA RNAME unix.hbz-nrw.de means unix@hbz-nrw.de.
  • ✓ Date-based serial #26
    The serial 2026102100 follows the YYYYMMDDnn convention (2026-10-21).

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

pass

17 records at the apex

Found

Read from
134.95.44.35:53
TypeValueTTL
SOAns00.hbz-nrw.de. unix.hbz-nrw.de. 2026102100 7200 2400 3600000 360086400
NSdns1.uni-koeln.de.86400
NSnse04.hbz-nrw.de.86400
NSnse03.hbz-nrw.de.86400
A193.30.112.1586400
MX100 mx03.hbz-nrw.de.86400
MX100 mx01.hbz-nrw.de.86400
MX100 mx02.hbz-nrw.de.86400
TXT"HARICA-tY4kLghMKSHkizlagiI"86400
TXT"v=spf1 ip4:193.30.112.0/24 mx ~all"86400
TXT"google-site-verification=PxANFQ-C5L7jZ_9co-mv_z-p134KM87w-G2_R6v8WNk"86400
TXT"miro-verification=49ced2dfc3e42f0d5321c8e4f15870c2e1a93162"86400
TXT"MS=D20C5AB9259C06B5CD28C9EA2D7A3D628FD60399"86400
CAA0 iodef "mailto:pki@hbz-nrw.de"86400
CAA0 issue "sectigo.com"86400
CAA0 issue "harica.gr"86400
CAA0 issue "pki.dfn.de"86400

Checks

  • ✓ TTLs within range #32
    TTLs: A 1d, MX 1d, NS 1d.
  • ✓ No CNAME at the apex #33
    The zone apex has no CNAME record.
  • ✓ No wildcard #34
    Names that don't exist return NXDOMAIN.
  • ✓ CAA restricts issuance #35
    Certificates may be issued by: sectigo.com, harica.gr, pki.dfn.de.