uni-rostock.de

Checked 22 October 2026, 00:50 UTC · via 8.8.8.8
!Passed with warnings
25 passed 1 warning 0 failed 7 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

dns-2.dfn.de, dns-3.dfn.de, george.ns.uni-rostock.de, ringo.ns.uni-rostock.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-2.dfn.de, dns-3.dfn.de, george.ns.uni-rostock.de, ringo.ns.uni-rostock.de
NS in the zone
dns-2.dfn.de, dns-3.dfn.de, george.ns.uni-rostock.de, ringo.ns.uni-rostock.de
NameserverAddressesNetwork (AS)Glue
dns-2.dfn.de193.174.75.54 2001:638:d:b102::1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
dns-3.dfn.de193.174.75.58 2001:638:d:b103::1AS680 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.de139.30.255.118 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., DE139.30.255.118 2001:638:804:bf::118
ringo.ns.uni-rostock.de139.30.255.117 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., DE139.30.255.117 2001:638:804:bf::117

Checks

  • ✓ 4 nameservers #6
    Delegated to dns-2.dfn.de, dns-3.dfn.de, george.ns.uni-rostock.de, ringo.ns.uni-rostock.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: george.ns.uni-rostock.de, ringo.ns.uni-rostock.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 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): 8 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

info

8 of 8 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns-2.dfn.de 193.174.75.54NOERROR, 7 ms, authoritativenoyes / yesrefused0
dns-2.dfn.de 2001:638:d:b102::1NOERROR, 7 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 193.174.75.58NOERROR, 8 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 2001:638:d:b103::1NOERROR, 10 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, 20 ms, authoritativenoyes / yesrefused-

Checks

  • ✓ All respond #14
    All 8 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.
  • i
    Identifying string disclosed
    These nameservers answer version queries with a string that is not a version number: dns-2.dfn.de: "0"; dns-3.dfn.de: "0".
    #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 2012065892 · primary john.ns.uni-rostock.de

Found

Primary (MNAME)
john.ns.uni-rostock.de
Contact (RNAME)
hostmaster.uni-rostock.de
Serial
2012065892
Refresh / retry
86400 s / 300 s
Expire
604800 s
Negative TTL
900 s

Serial per nameserver

NameserverSerial
dns-2.dfn.de (193.174.75.54)2012065892
dns-2.dfn.de (2001:638:d:b102::1)2012065892
dns-3.dfn.de (193.174.75.58)2012065892
dns-3.dfn.de (2001:638:d:b103::1)2012065892
george.ns.uni-rostock.de (139.30.255.118)2012065892
george.ns.uni-rostock.de (2001:638:804:bf::118)2012065892
ringo.ns.uni-rostock.de (139.30.255.117)2012065892
ringo.ns.uni-rostock.de (2001:638:804:bf::117)2012065892

Checks

  • ✓ Serial 2012065892 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 1d, retry 5m, expire 7d, negative TTL 15m.
  • i
    Hidden master
    The primary nameserver john.ns.uni-rostock.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-rostock.de #25
    The SOA RNAME hostmaster.uni-rostock.de means hostmaster@uni-rostock.de.
  • ✓ Timestamp serial #26
    The serial 2012065892 is a Unix timestamp (2033-10-04 19:11 UTC).

DNSSEC

warn

Signed, DS published at parent

Found

Validated by resolver
yes
Denial of existence
NSEC
Signatures valid until
27 October 2026

DS at the parent

Key tagAlgorithmDigestMatches a key
21477RSASHA512 (10)SHA256 BBAD0CAB802060A8…yes

DNSKEY in the zone

Key tagRoleAlgorithm
55427ZSK (256)RSASHA512 (10)
11417ZSK (256)RSASHA512 (10)
21477KSK (257)RSASHA512 (10)

Checks

  • ✓ Signed and validated #27
    The zone is signed, the parent publishes a DS record, and the resolver validates the answers.
  • ✓ DS matches a key #28
    The DS record at the parent matches a key in the zone: key tag 21477 (SHA256).
  • ✓ Modern algorithms #29
    Key algorithms: RSASHA512 (10).
  • !
    Signatures expire soon
    The earliest signature expires at 2026-10-27 14:25 UTC (in 134h0m0s). Check that automatic re-signing works.
    #30
  • i
    NSEC
    The zone uses NSEC, so its full contents can be listed by walking the NSEC chain. That is fine unless the names are sensitive.
    #31

Records

pass

22 records at the apex

Found

Read from
193.174.75.54:53
TypeValueTTL
SOAjohn.ns.uni-rostock.de. hostmaster.uni-rostock.de. 2012065892 86400 300 604800 9007200
NSdns-2.dfn.de.7200
NSdns-3.dfn.de.7200
NSringo.ns.uni-rostock.de.7200
NSgeorge.ns.uni-rostock.de.7200
A139.30.8.197172800
A139.30.8.153172800
A139.30.8.152172800
A139.30.8.196172800
MX10 mx2.uni-rostock.de.7200
MX5 mx1.uni-rostock.de.7200
TXT"TXTZOOM_verify_RBHDhK77QbmEWRSc3JN8pg"3600
TXT"google-site-verification=xykf6VmwCmui4cBckweGaJqNEpDTOLdqlS6bqJIDqfc"3600
TXT"adobe-idp-site-verification=9f1ea13e1965e7ba49e0fc892da30b967634e81a9a0c7782d3f422d859457800"3600
TXT"MS=EBB25037A5FEEDC4B5353D3D9693CFEB6CC8EBC5"3600
TXT"cisco-ci-domain-verification=56a20d58ea7bd3a5bd82ae4ea8fb9869e9449263cd1198a6c907dbf707d4ee80"3600
TXT"v=spf1 include:_spf.uni-rostock.de include:med.uni-rostock.de include:uni-greifswald.de ~all"3600
TXT"autodesk-domain-verification=2v44WtlapjaaOB1TEQ06"3600
CAA0 iodef "mailto:noc@uni-rostock.de"7200
CAA0 issue "harica.gr"7200
CAA0 issue "letsencrypt.org"7200
CAA0 issue "pki.dfn.de"7200

Checks

  • ✓ TTLs within range #32
    TTLs: A 2d, MX 2h, NS 2h. The NS TTL at the parent is 1d and in the zone 2h; 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.
  • ✓ CAA restricts issuance #35
    Certificates may be issued by: harica.gr, letsencrypt.org, pki.dfn.de.