adtech.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

ns1.yahoo.com, ns2.yahoo.com, ns3.yahoo.com, ns4.yahoo.com, ns5.yahoo.com

Found

Parent zone

de

Delegation from

a.nic.de (194.0.0.53)

NS at the parent

ns1.yahoo.com, ns2.yahoo.com, ns3.yahoo.com, ns4.yahoo.com, ns5.yahoo.com

NS in the zone

ns1.yahoo.com, ns2.yahoo.com, ns3.yahoo.com, ns4.yahoo.com, ns5.yahoo.com

Checks

• ✓ 5 nameservers #6

  Delegated to ns1.yahoo.com, ns2.yahoo.com, ns3.yahoo.com, ns4.yahoo.com, ns5.yahoo.com.
• ✓ 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 5 IPv4 /24s and 4 IPv6 /48s.
• ✓ 5 autonomous systems #11

  The nameservers are spread over: AS10310 (YAHOO-1 - Yahoo Holdings Inc., US): 1 address; AS10880 (YAHOO-AN2 - Yahoo Holdings Inc., US): 3 addresses; AS23879 (YAHOO-INY - INY Edge site, US): 2 addresses; AS36646 (YAHOO-NE1 - Yahoo Holdings Inc., US): 1 address; AS7280 (YAHOO-FC - Yahoo Holdings Inc., US): 2 addresses.
• i

  All nameserver names under .com

  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: ns4.yahoo.com.

  #13

9 of 9 addresses answer authoritatively

Found

Checks

• ✓ All respond #14

  All 9 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: ns1.yahoo.com: "Yahoo"; ns2.yahoo.com: "Yahoo"; ns3.yahoo.com: "Yahoo"; ns4.yahoo.com: "Yahoo"; ns5.yahoo.com: "Yahoo".

  #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.

serial 2026101601 · primary hidden-master.yahoo.com

Found

Primary (MNAME)

hidden-master.yahoo.com

Contact (RNAME)

hostmaster.yahoo-inc.com

Serial

2026101601

Refresh / retry

28800 s / 7200 s

Expire

604800 s

Negative TTL

600 s

Serial per nameserver

Checks

• ✓ Serial 2026101601 everywhere #22

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

  SOA refresh 8h, retry 2h, expire 7d, negative TTL 10m.
• i

  Hidden master

  The primary nameserver hidden-master.yahoo.com 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@yahoo-inc.com #25

  The SOA RNAME hostmaster.yahoo-inc.com means hostmaster@yahoo-inc.com.
• ✓ Date-based serial #26

  The serial 2026101601 follows the YYYYMMDDnn convention (2026-10-16).