upb.de

Checked 22 October 2026, 00:50 UTC · via 8.8.8.8
!Passed with warnings
21 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

dius.uni-paderborn.de, dns-1.dfn.de, dufu.uni-paderborn.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dius.uni-paderborn.de, dns-1.dfn.de, dufu.uni-paderborn.de
NS in the zone
dius.uni-paderborn.de, dns-1.dfn.de, dufu.uni-paderborn.de
NameserverAddressesNetwork (AS)Glue
dius.uni-paderborn.de131.234.200.36 2001:638:502:c069::36AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE131.234.200.36 2001:638:502:c069::36
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-
dufu.uni-paderborn.de131.234.200.52 2001:638:502:c06a::52AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE131.234.200.52 2001:638:502:c06a::52

Checks

  • ✓ 3 nameservers #6
    Delegated to dius.uni-paderborn.de, dns-1.dfn.de, dufu.uni-paderborn.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): 6 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

6 of 6 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dius.uni-paderborn.de 131.234.200.36NOERROR, 11 ms, authoritativenoyes / yesrefused-
dius.uni-paderborn.de 2001:638:502:c069::36NOERROR, 12 ms, authoritativenoyes / yesrefused-
dns-1.dfn.de 193.174.75.50NOERROR, 12 ms, authoritativenoyes / yesrefused0
dns-1.dfn.de 2001:638:d:b101::1NOERROR, 12 ms, authoritativenoyes / yesrefused0
dufu.uni-paderborn.de 131.234.200.52NOERROR, 12 ms, authoritativenoyes / yesrefused-
dufu.uni-paderborn.de 2001:638:502:c06a::52NOERROR, 12 ms, authoritativenoyes / yesrefused-

Checks

  • ✓ All respond #14
    All 6 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".
    #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 767261065 · primary dius.uni-paderborn.de

Found

Primary (MNAME)
dius.uni-paderborn.de
Contact (RNAME)
hostmaster.uni-paderborn.de
Serial
767261065
Refresh / retry
10800 s / 3600 s
Expire
604800 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
dius.uni-paderborn.de (131.234.200.36)767261065
dius.uni-paderborn.de (2001:638:502:c069::36)767261065
dns-1.dfn.de (193.174.75.50)767261065
dns-1.dfn.de (2001:638:d:b101::1)767261065
dufu.uni-paderborn.de (131.234.200.52)767261065
dufu.uni-paderborn.de (2001:638:502:c06a::52)767261065

Checks

  • ✓ Serial 767261065 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 3h, retry 1h, expire 7d, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver dius.uni-paderborn.de is one of the listed nameservers.
  • ✓ Contact hostmaster@uni-paderborn.de #25
    The SOA RNAME hostmaster.uni-paderborn.de means hostmaster@uni-paderborn.de.
  • ✓ Counter serial #26
    The serial 767261065 is a plain counter.

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

11 records at the apex

Found

Read from
131.234.200.36:53
TypeValueTTL
SOAdius.uni-paderborn.de. hostmaster.uni-paderborn.de. 767261065 10800 3600 604800 36003600
NSdius.uni-paderborn.de.86400
NSdns-1.dfn.de.86400
NSdufu.uni-paderborn.de.86400
A131.234.196.273600
AAAA2001:638:502:c036::273600
MX0 mail.uni-paderborn.de.3600
TXT"bw=cLqlIr7RU0FSzxt5XO9fjxmtf7vwxZsZQFYyCJkRdPnu"3600
TXT"v=spf1 include:mail.uni-paderborn.de -all"3600
TXT"adobe-idp-site-verification=c3f69f1d645ad1263241f5fd6d114d7bddf26579871d8118f70d2d44e90a52c4"3600
TXT"atlassian-domain-verification=NzrKew46SjAClUnQSu5Qax4dsd5JU58NfGIc9SmhF1ZBfo7gYc4kK7RvisQGlbJw"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 1h, AAAA 1h, MX 1h, NS 1d.
  • ✓ No CNAME at the apex #33
    The zone apex has no CNAME record.
  • i
    Wildcard record
    A random name under the zone resolves, so there is a wildcard (*) record. Typos and non-existent hosts resolve too, which can confuse mail and certificate checks.
    #34
  • 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