idioma.nl

ns17.csv-networks.nl, ns18.csv-networks.nl

Found

Parent zone

nl

Delegation from

ns1.dns.nl (194.0.28.53)

NS at the parent

ns17.csv-networks.nl, ns18.csv-networks.nl

NS in the zone

ns17.csv-networks.nl, ns18.csv-networks.nl

Checks

• i

  2 nameservers

  Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: ns17.csv-networks.nl, ns18.csv-networks.nl.

  #6
• ✓ 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 one network

  all IPv4 addresses are in 84.244.151.0/24. A single network failure takes all nameservers down; RFC 2182 recommends topologically separate networks (anycast setups are an exception).

  #10
• i

  All nameservers in one AS

  All nameserver addresses are announced by one network operator (AS20495 (WEDARE - We Dare B.V., NL): 2 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 .nl

  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
• !

  No IPv6

  None of the nameservers has an IPv6 address, so IPv6-only resolvers can't reach them.

  #13

2 of 2 addresses answer authoritatively

Found

Checks

• ✓ All respond #14

  All 2 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: ns17.csv-networks.nl: "9.11.36-RedHat-9.11.36-16.el8_10.16"; ns18.csv-networks.nl: "9.11.36-RedHat-9.11.36-16.el8_10.16". 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 2026091805 · primary ns17.csv-networks.nl

Found

Primary (MNAME)

ns17.csv-networks.nl

Contact (RNAME)

root.idioma.nl

Serial

2026091805

Refresh / retry

3600 s / 3600 s

Expire

1209600 s

Negative TTL

1800 s

Serial per nameserver

Checks

• ✓ Serial 2026091805 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 14d, negative TTL 30m.

  #23
• ✓ Primary is a public nameserver #24

  The primary nameserver ns17.csv-networks.nl is one of the listed nameservers.
• ✓ Contact root@idioma.nl #25

  The SOA RNAME root.idioma.nl means root@idioma.nl.
• ✓ Date-based serial #26

  The serial 2026091805 follows the YYYYMMDDnn convention (2026-09-18).

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