natuurkunde.nl

Checked 22 October 2026, 14:40 UTC · via 8.8.8.8
!Passed with warnings
20 passed 2 warnings 0 failed 7 info

Registration

info

.nl country-code

Found

TLD
.nl (country-code)
ICANN policies apply
no
Lookup error: https://rdap.sidn.nl/domain/natuurkunde.nl returned HTTP 429

Checks

  • i
    .nl 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
    .nl is delegated in the root zone and DNSSEC-signed.
  • i
    Could not be checked
    The RDAP lookup failed, so this could not be checked: https://rdap.sidn.nl/domain/natuurkunde.nl returned HTTP 429
    #3

Delegation

warn

cesano.nikhef.nl, dwalin.nikhef.nl

Found

Parent zone
nl
Delegation from
ns1.dns.nl (194.0.28.53)
NS at the parent
cesano.nikhef.nl, dwalin.nikhef.nl
NS in the zone
cesano.nikhef.nl, dwalin.nikhef.nl
NameserverAddressesNetwork (AS)Glue
cesano.nikhef.nl192.16.185.12 2001:610:120:1001::185:12AS1104 Nikhef - Stichting Nederlandse Wetenschappelijk Onderzoek Instituten, NL AS1103 SURFNET-NL - SURF B.V., NL192.16.185.12
dwalin.nikhef.nl192.16.199.17 2001:610:120:1000::199:17AS1104 Nikhef - Stichting Nederlandse Wetenschappelijk Onderzoek Instituten, NL AS1103 SURFNET-NL - SURF B.V., NL192.16.199.17 2001:610:120:1000::199:17

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: cesano.nikhef.nl, dwalin.nikhef.nl.
    #6
  • ✓ 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: cesano.nikhef.nl (glue 192.16.185.12, zone 192.16.185.12, 2001:610:120:1001::185:12). 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 2001:610:120::/48, while the other address family is spread over several networks.
    #10
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS1103 (SURFNET-NL - SURF B.V., NL): 2 addresses; AS1104 (Nikhef - Stichting Nederlandse Wetenschappelijk Onderzoek Instituten, NL): 2 addresses.
  • 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
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

pass

4 of 4 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
cesano.nikhef.nl 192.16.185.12NOERROR, 10 ms, authoritativenoyes / yesrefused-
cesano.nikhef.nl 2001:610:120:1001::185:12NOERROR, 10 ms, authoritativenoyes / yesrefused-
dwalin.nikhef.nl 192.16.199.17NOERROR, 10 ms, authoritativenoyes / yesrefused-
dwalin.nikhef.nl 2001:610:120:1000::199:17NOERROR, 10 ms, authoritativenoyes / yesrefused-

Checks

  • ✓ All respond #14
    All 4 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.
  • ✓ No version disclosed #17
    The nameservers don't reveal their software version.
  • ✓ 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.

SOA

info

serial 20230007 · primary lin-vm-net-ctb-001.nikhef.nl

Found

Primary (MNAME)
lin-vm-net-ctb-001.nikhef.nl
Contact (RNAME)
hostmaster.nikhef.nl
Serial
20230007
Refresh / retry
14400 s / 3600 s
Expire
604800 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
cesano.nikhef.nl (192.16.185.12)20230007
cesano.nikhef.nl (2001:610:120:1001::185:12)20230007
dwalin.nikhef.nl (192.16.199.17)20230007
dwalin.nikhef.nl (2001:610:120:1000::199:17)20230007

Checks

  • ✓ Serial 20230007 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 4h, retry 1h, expire 7d, negative TTL 1d.
  • i
    Hidden master
    The primary nameserver lin-vm-net-ctb-001.nikhef.nl 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@nikhef.nl #25
    The SOA RNAME hostmaster.nikhef.nl means hostmaster@nikhef.nl.
  • ✓ Counter serial #26
    The serial 20230007 is a plain counter.

DNSSEC

warn

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

Records

info

7 records at the apex

Found

Read from
192.16.185.12:53
TypeValueTTL
SOAlin-vm-net-ctb-001.nikhef.nl. hostmaster.nikhef.nl. 20230007 14400 3600 604800 8640086400
NSdwalin.nikhef.nl.86400
NScesano.nikhef.nl.86400
A188.166.128.16786400
MX10 mx.soverin.net.86400
TXT"v=spf1 include:spf.mandrillapp.com ?all"86400
TXT"google-site-verification=eSl2iyLulRhE7Zz6vhalQ5vkWkycoYbFXf4AvpdMLOg"86400

Checks

  • ✓ TTLs within range #32
    TTLs: A 1d, MX 1d, NS 1d. The NS TTL at the parent is 1h and in the zone 1d; resolvers may use either.
  • ✓ 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