umm.de

gate4.umm.de, ns.she.de, ns1.twl-kom.de, ns2.she.de, ns3.twl-kom.de

Found

Parent zone

de

Delegation from

a.nic.de (194.0.0.53)

NS at the parent

gate4.umm.de, ns.she.de, ns1.twl-kom.de, ns2.she.de, ns3.twl-kom.de

NS in the zone

gate4.umm.de, ns.she.de, ns1.twl-kom.de, ns2.she.de, ns3.twl-kom.de

Checks

• ✓ 5 nameservers #6

  Delegated to gate4.umm.de, ns.she.de, ns1.twl-kom.de, ns2.she.de, ns3.twl-kom.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: ns1.twl-kom.de (glue 217.151.144.10, zone 217.151.144.10, 2a00:e58:1:9:217:151:144:10). Update the glue at your registrar.

  #8
• ✓ 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 2 IPv6 /48s.
• ✓ 4 autonomous systems #11

  The nameservers are spread over: AS12843 (TELEMAXX - TelemaxX Telekommunikation GmbH, DE): 1 address; AS553 (BELWUE - Universitaet Stuttgart, DE): 1 address; AS6786 (CRONON-BERLIN-AS - Cronon GmbH, DE): 1 address; AS9022 (TWL-KOM-AS - TWL-KOM GmbH, DE): 4 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
• i

  Partly IPv6

  These nameservers have no IPv6 address: gate4.umm.de, ns2.she.de, ns3.twl-kom.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: gate4.umm.de: "9.20.23". 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.

serial 2026090201 · primary gate4.umm.de

Found

Primary (MNAME)

gate4.umm.de

Contact (RNAME)

root.gate4.umm.de

Serial

2026090201

Refresh / retry

3600 s / 3600 s

Expire

1814400 s

Negative TTL

3600 s

Serial per nameserver

Checks

• ✓ Serial 2026090201 everywhere #22

  All nameservers serve the same version of the zone.
• !

  Unusual SOA timers

  retry 1h should be shorter than refresh 1h. Current values: refresh 1h, retry 1h, expire 21d, negative TTL 1h.

  #23
• ✓ Primary is a public nameserver #24

  The primary nameserver gate4.umm.de is one of the listed nameservers.
• ✓ Contact root@gate4.umm.de #25

  The SOA RNAME root.gate4.umm.de means root@gate4.umm.de.
• ✓ Date-based serial #26

  The serial 2026090201 follows the YYYYMMDDnn convention (2026-09-02).

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