uni-bielefeld.de

.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

dns-2.dfn.de, ns1.uni-bielefeld.de, ns2.uni-bielefeld.de

Found

Parent zone

de

Delegation from

a.nic.de (194.0.0.53)

NS at the parent

dns-2.dfn.de, ns1.uni-bielefeld.de, ns2.uni-bielefeld.de

NS in the zone

dns-2.dfn.de, ns1.uni-bielefeld.de, ns2.uni-bielefeld.de

Checks

• ✓ 3 nameservers #6

  Delegated to dns-2.dfn.de, ns1.uni-bielefeld.de, ns2.uni-bielefeld.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: ns1.uni-bielefeld.de, ns2.uni-bielefeld.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): 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.

6 of 6 addresses answer authoritatively

Found

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-2.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.

Signed, DS published at parent

Found

Validated by resolver

yes

Denial of existence

NSEC3

NSEC3

0 iterations, 0-byte salt

Signatures valid until

19 November 2026

DS at the parent

DNSKEY in the zone

Checks

• ✓ Signed and validated #27

  The zone is signed, the parent publishes a DS record, and the resolver validates the answers.
• i

  Unused DS records

  These DS records match no key in the zone: key tag 7884 (SHA256). That is normal during a key rollover; otherwise remove them.

  #28
• ✓ Modern algorithms #29

  Key algorithms: RSASHA512 (10).
• ✓ Signatures valid until 2026-11-19 #30

  The earliest DNSKEY/SOA signature expires at 2026-11-19 17:06 UTC.
• ✓ NSEC3 as recommended #31

  The zone uses NSEC3 with 0 iterations and no salt (RFC 9276).