sciebo.de

Checked 22 October 2026, 00:02 UTC · via 8.8.8.8
!Passed with warnings
23 passed 1 warning 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

dns-1.dfn.de, dns-2.dfn.de, ns01-ext.uni-muenster.de, ns02-ext.uni-muenster.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-1.dfn.de, dns-2.dfn.de, ns01-ext.uni-muenster.de, ns02-ext.uni-muenster.de
NS in the zone
dns-1.dfn.de, dns-2.dfn.de, ns01-ext.uni-muenster.de, ns02-ext.uni-muenster.de
NameserverAddressesNetwork (AS)Glue
dns-1.dfn.de193.174.75.50 2001:638:d:b101::1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
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-
ns01-ext.uni-muenster.de128.176.0.100 2001:4cf0:0:1120::53AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE128.176.0.100 2001:4cf0:0:1120::53
ns02-ext.uni-muenster.de128.176.0.116 2001:4cf0:0:1220::53AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE128.176.0.116 2001:4cf0:0:1220::53

Checks

  • ✓ 4 nameservers #6
    Delegated to dns-1.dfn.de, dns-2.dfn.de, ns01-ext.uni-muenster.de, ns02-ext.uni-muenster.de.
  • ✓ 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.
  • ✓ 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-1.dfn.de 193.174.75.50NOERROR, 14 ms, authoritativenoyes / yesrefused0
dns-1.dfn.de 2001:638:d:b101::1NOERROR, 14 ms, authoritativenoyes / yesrefused0
dns-2.dfn.de 193.174.75.54NOERROR, 6 ms, authoritativenoyes / yesrefused0
dns-2.dfn.de 2001:638:d:b102::1NOERROR, 7 ms, authoritativenoyes / yesrefused0
ns01-ext.uni-muenster.de 128.176.0.100NOERROR, 11 ms, authoritativenoyes / yesrefusedNot supported
ns01-ext.uni-muenster.de 2001:4cf0:0:1120::53NOERROR, 11 ms, authoritativenoyes / yesrefusedNot supported
ns02-ext.uni-muenster.de 128.176.0.116NOERROR, 9 ms, authoritativenoyes / yesrefusedNot supported
ns02-ext.uni-muenster.de 2001:4cf0:0:1220::53NOERROR, 12 ms, authoritativenoyes / yesrefusedNot supported

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-1.dfn.de: "0"; dns-2.dfn.de: "0"; ns01-ext.uni-muenster.de: "Not supported"; ns02-ext.uni-muenster.de: "Not supported".
    #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 2026417722 · primary ns01-ext.uni-muenster.de

Found

Primary (MNAME)
ns01-ext.uni-muenster.de
Contact (RNAME)
noc.uni-muenster.de
Serial
2026417722
Refresh / retry
7200 s / 1800 s
Expire
3600000 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
dns-1.dfn.de (193.174.75.50)2026417722
dns-1.dfn.de (2001:638:d:b101::1)2026417722
dns-2.dfn.de (193.174.75.54)2026417722
dns-2.dfn.de (2001:638:d:b102::1)2026417722
ns01-ext.uni-muenster.de (128.176.0.100)2026417722
ns01-ext.uni-muenster.de (2001:4cf0:0:1120::53)2026417722
ns02-ext.uni-muenster.de (128.176.0.116)2026417722
ns02-ext.uni-muenster.de (2001:4cf0:0:1220::53)2026417722

Checks

  • ✓ Serial 2026417722 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 2h, retry 30m, expire 1000h, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns01-ext.uni-muenster.de is one of the listed nameservers.
  • ✓ Contact noc@uni-muenster.de #25
    The SOA RNAME noc.uni-muenster.de means noc@uni-muenster.de.
  • ✓ Timestamp serial #26
    The serial 2026417722 is a Unix timestamp (2034-03-19 21:48 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

pass

17 records at the apex

Found

Read from
193.174.75.50:53
TypeValueTTL
SOAns01-ext.uni-muenster.de. noc.uni-muenster.de. 2026417722 7200 1800 3600000 36003600
NSns01-ext.uni-muenster.de.3600
NSns02-ext.uni-muenster.de.3600
NSdns-1.dfn.de.3600
NSdns-2.dfn.de.3600
A128.176.1.43600
MX100 udcm-wwu3.uni-muenster.de.3600
MX100 udcm-wwu2.uni-muenster.de.3600
MX100 udcm-wwu1.uni-muenster.de.3600
MX100 udcm-wwu4.uni-muenster.de.3600
TXT"v=spf1 ip4:128.176.0.0/16 ip6:2001:4cf0::/29 ?all"3600
CAA0 issue "harica.gr"3600
CAA0 iodef "mailto:ca@uni-muenster.de"3600
CAA0 issuewild ";"3600
CAA0 issuemail "pki.dfn.de"3600
CAA0 issue "pki.dfn.de"3600
CAA0 issuemail "harica.gr"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 1h, MX 1h, NS 1h. The NS TTL at the parent is 1d and in the zone 1h; 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, none (issuance forbidden), pki.dfn.de.