goethe-university-frankfurt.de

chaplin.rz.uni-frankfurt.de, warumdenn.rz.uni-frankfurt.de, wattdenn.rz.uni-frankfurt.de, weshalbdenn.rz.uni-frankfurt.de, wiesodenn.rz.uni-frankfurt.de

Found

Parent zone

de

Delegation from

a.nic.de (194.0.0.53)

NS at the parent

chaplin.rz.uni-frankfurt.de, warumdenn.rz.uni-frankfurt.de, wattdenn.rz.uni-frankfurt.de, weshalbdenn.rz.uni-frankfurt.de, wiesodenn.rz.uni-frankfurt.de

NS in the zone

chaplin.rz.uni-frankfurt.de, warumdenn.rz.uni-frankfurt.de, wattdenn.rz.uni-frankfurt.de, weshalbdenn.rz.uni-frankfurt.de, wiesodenn.rz.uni-frankfurt.de

Checks

• ✓ 5 nameservers #6

  Delegated to chaplin.rz.uni-frankfurt.de, warumdenn.rz.uni-frankfurt.de, wattdenn.rz.uni-frankfurt.de, weshalbdenn.rz.uni-frankfurt.de, wiesodenn.rz.uni-frankfurt.de.
• ✓ Parent and zone agree #7

  The parent delegation and the zone's NS records list the same nameservers.
• !

  Glue differs from the zone

  The addresses at the parent (glue) differ from the addresses in the zone: chaplin.rz.uni-frankfurt.de (glue 141.2.22.74, zone 141.2.22.74, 2001:a38:1001:3109::42); wattdenn.rz.uni-frankfurt.de (glue 141.2.149.10, zone 141.2.149.10, 2001:a38:1001:3110::42). Update the glue at your registrar.

  #8
• ✓ All names resolve #9

  Every nameserver name has an address and is not an alias.
• i

  One address family in one network

  all IPv6 addresses are in 2001:a38:1001::/48, while the other address family is spread over several networks.

  #10
• i

  All nameservers in one AS

  All nameserver addresses are announced by one network operator (AS20633 (UNIFFM-NET - Johann Wolfgang Goethe-Universitat Frankfurt am Main, 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: warumdenn.rz.uni-frankfurt.de, weshalbdenn.rz.uni-frankfurt.de, wiesodenn.rz.uni-frankfurt.de.

  #13

7 of 7 addresses answer authoritatively

Found

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: warumdenn.rz.uni-frankfurt.de: "PowerDNS Authoritative Server 5.0.8 (built Oct 7 2026 06:20:49 by root@localhost)"; weshalbdenn.rz.uni-frankfurt.de: "PowerDNS Authoritative Server 5.0.8 (built Oct 7 2026 06:20:49 by root@localhost)"; wiesodenn.rz.uni-frankfurt.de: "PowerDNS Authoritative Server 5.0.8 (built Oct 7 2026 06:20:49 by root@localhost)". 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.

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