rostock.de

Checked 22 October 2026, 00:01 UTC · via 8.8.8.8
✗Problems found
19 passed 3 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

fail

deneb.dfn.de, primary.ns.uni-rostock.de, rz.rostock.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
deneb.dfn.de, primary.ns.uni-rostock.de, rz.rostock.de
NS in the zone
deneb.dfn.de, george.ns.uni-rostock.de, ringo.ns.uni-rostock.de, rz.rostock.de
NameserverAddressesNetwork (AS)Glue
deneb.dfn.de192.76.176.9 2001:638:800:1::9AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
george.ns.uni-rostock.de (zone only)139.30.255.118 2001:638:804:bf::118AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
primary.ns.uni-rostock.de (parent only)(does not resolve)-
ringo.ns.uni-rostock.de (zone only)139.30.255.117 2001:638:804:bf::117AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
rz.rostock.de195.37.188.162AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE195.37.188.162

Checks

  • ✓ 3 nameservers #6
    Delegated to deneb.dfn.de, primary.ns.uni-rostock.de, rz.rostock.de.
  • !
    NS sets differ
    The nameservers at the parent and in the zone should be the same. Only at the parent: primary.ns.uni-rostock.de; only in the zone: george.ns.uni-rostock.de, ringo.ns.uni-rostock.de. deneb.dfn.de, george.ns.uni-rostock.de, ringo.ns.uni-rostock.de, rz.rostock.de report NS deneb.dfn.de george.ns.uni-rostock.de ringo.ns.uni-rostock.de rz.rostock.de.
    #7
  • ✓ Glue present and correct #8
    Glue is published for the nameservers inside the zone: rz.rostock.de.
  • ✗
    Nameserver names don't resolve
    These nameservers have no A or AAAA record, so they can't be reached (lame delegation): primary.ns.uni-rostock.de.
    #9
  • ✓ Nameservers in different networks #10
    The nameservers are spread over 3 IPv4 /24s and 2 IPv6 /48s.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE): 7 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
  • i
    Partly IPv6
    These nameservers have no IPv6 address: rz.rostock.de.
    #13

Nameservers

warn

7 of 7 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
deneb.dfn.de 192.76.176.9NOERROR, 14 ms, authoritativenoyes / yesrefused0
deneb.dfn.de 2001:638:800:1::9NOERROR, 14 ms, authoritativenoyes / yesrefused0
george.ns.uni-rostock.de 139.30.255.118NOERROR, 20 ms, authoritativenoyes / yesrefused-
george.ns.uni-rostock.de 2001:638:804:bf::118NOERROR, 20 ms, authoritativenoyes / yesrefused-
ringo.ns.uni-rostock.de 139.30.255.117NOERROR, 20 ms, authoritativenoyes / yesrefused-
ringo.ns.uni-rostock.de 2001:638:804:bf::117NOERROR, 21 ms, authoritativenoyes / yesrefused-
rz.rostock.de 195.37.188.162NOERROR, 21 ms, authoritativenoyes / yesrefused9.20.15

Checks

  • ✓ All respond #14
    All 7 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: rz.rostock.de: "9.20.15". 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 2018073259 · primary rz.rostock.de

Found

Primary (MNAME)
rz.rostock.de
Contact (RNAME)
root.rostock.de
Serial
2018073259
Refresh / retry
14400 s / 3600 s
Expire
1209600 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
deneb.dfn.de (192.76.176.9)2018073259
deneb.dfn.de (2001:638:800:1::9)2018073259
george.ns.uni-rostock.de (139.30.255.118)2018073259
george.ns.uni-rostock.de (2001:638:804:bf::118)2018073259
ringo.ns.uni-rostock.de (139.30.255.117)2018073259
ringo.ns.uni-rostock.de (2001:638:804:bf::117)2018073259
rz.rostock.de (195.37.188.162)2018073259

Checks

  • ✓ Serial 2018073259 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 4h, retry 1h, expire 14d, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver rz.rostock.de is one of the listed nameservers.
  • ✓ Contact root@rostock.de #25
    The SOA RNAME root.rostock.de means root@rostock.de.
  • ✓ Timestamp serial #26
    The serial 2018073259 is a Unix timestamp (2033-12-13 07:54 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

10 records at the apex

Found

Read from
192.76.176.9:53
TypeValueTTL
SOArz.rostock.de. root.rostock.de. 2018073259 14400 3600 1209600 86400360
NSrz.rostock.de.360
NSdeneb.dfn.de.360
NSringo.ns.uni-rostock.de.360
NSgeorge.ns.uni-rostock.de.360
A144.76.121.156360
MX20 stadt5.rostock.de.360
MX10 stadt4.rostock.de.360
TXT"MS=ms43248879"360
TXT"v=spf1 mx -all"360

Checks

  • ✓ TTLs within range #32
    TTLs: A 6m, MX 6m, NS 6m. The NS TTL at the parent is 1d and in the zone 6m; 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