tu-dortmund.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-3.dfn.de, ns1.itmc.tu-dortmund.de, ns2.itmc.tu-dortmund.de, secondary.rrze.uni-erlangen.de

Found

Parent zone

de

Delegation from

a.nic.de (194.0.0.53)

NS at the parent

dns-3.dfn.de, ns1.itmc.tu-dortmund.de, ns2.itmc.tu-dortmund.de, secondary.rrze.uni-erlangen.de

NS in the zone

dns-3.dfn.de, ns1.itmc.tu-dortmund.de, ns2.itmc.tu-dortmund.de, secondary.rrze.uni-erlangen.de

Checks

• ✓ 4 nameservers #6

  Delegated to dns-3.dfn.de, ns1.itmc.tu-dortmund.de, ns2.itmc.tu-dortmund.de, secondary.rrze.uni-erlangen.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.itmc.tu-dortmund.de, ns2.itmc.tu-dortmund.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 5 IPv4 /24s and 4 IPv6 /48s.
• ✓ 2 autonomous systems #11

  The nameservers are spread over: AS29484 (RUB-AS - Ruhr-Universitaet Bochum, DE): 2 addresses; AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE): 8 addresses.
• 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.

serial 596682151 · primary ns0.itmc.tu-dortmund.de

Found

Primary (MNAME)

ns0.itmc.tu-dortmund.de

Contact (RNAME)

hostmaster.tu-dortmund.de

Serial

596682151

Refresh / retry

21600 s / 3600 s

Expire

1728000 s

Negative TTL

10800 s

Serial per nameserver

Checks

• ✓ Serial 596682151 everywhere #22

  All nameservers serve the same version of the zone.
• ✓ Timers within recommendations #23

  SOA refresh 6h, retry 1h, expire 20d, negative TTL 3h.
• i

  Hidden master

  The primary nameserver ns0.itmc.tu-dortmund.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@tu-dortmund.de #25

  The SOA RNAME hostmaster.tu-dortmund.de means hostmaster@tu-dortmund.de.
• ✓ Counter serial #26

  The serial 596682151 is a plain counter.

23 records at the apex

Found

Read from

193.174.75.58:53

Checks

• ✓ TTLs within range #32

  TTLs: A 10m, AAAA 10m, MX 1d, NS 1d.
• ✓ No CNAME at the apex #33

  The zone apex has no CNAME record.
• ✓ No wildcard #34

  Names that don't exist return NXDOMAIN.
• 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