theorie-leren.nl

Checked 22 October 2026, 16:31 UTC · via 8.8.8.8
iAll checks passed
30 passed 0 warnings 0 failed 3 info

Registration

info

.nl country-code

Found

TLD
.nl (country-code)
ICANN policies apply
no
Lookup error: https://rdap.sidn.nl/domain/theorie-leren.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/theorie-leren.nl returned HTTP 429
    #3

Delegation

pass

nsauth0.cyberfusion.nl, nsauth1.cyberfusion.nl, nsauth2.cyberfusion.nu

Found

Parent zone
nl
Delegation from
ns1.dns.nl (194.0.28.53)
NS at the parent
nsauth0.cyberfusion.nl, nsauth1.cyberfusion.nl, nsauth2.cyberfusion.nu
NS in the zone
nsauth0.cyberfusion.nl, nsauth1.cyberfusion.nl, nsauth2.cyberfusion.nu
NameserverAddressesNetwork (AS)Glue
nsauth0.cyberfusion.nl185.233.173.153 2a0c:eb00:0:f10:185:233:173:153AS204983 Cyberfusion - Cyberfusion B.V., NL AS204983 Cyberfusion - Cyberfusion B.V., NL185.233.173.153 2a0c:eb00:0:f10:185:233:173:153
nsauth1.cyberfusion.nl185.233.173.150 2a0c:eb00:0:f10:185:233:173:150AS204983 Cyberfusion - Cyberfusion B.V., NL AS204983 Cyberfusion - Cyberfusion B.V., NL185.233.173.150 2a0c:eb00:0:f10:185:233:173:150
nsauth2.cyberfusion.nu149.210.201.179 2a01:7c8:aab8:81:5054:ff:fec4:9ca8AS20857 TRANSIP-AS - Signet B.V., NL AS20857 TRANSIP-AS - Signet B.V., NL-

Checks

  • ✓ 3 nameservers #6
    Delegated to nsauth0.cyberfusion.nl, nsauth1.cyberfusion.nl, nsauth2.cyberfusion.nu.
  • ✓ 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 2 IPv4 /24s and 2 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS204983 (Cyberfusion - Cyberfusion B.V., NL): 4 addresses; AS20857 (TRANSIP-AS - Signet B.V., NL): 2 addresses.
  • ✓ Nameserver names under 2 TLDs #12
    Nameserver names use the TLDs .nl, .nu.
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

pass

6 of 6 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
nsauth0.cyberfusion.nl 185.233.173.153NOERROR, 13 ms, authoritativenoyes / yesrefused-
nsauth0.cyberfusion.nl 2a0c:eb00:0:f10:185:233:173:153NOERROR, 14 ms, authoritativenoyes / yesrefused-
nsauth1.cyberfusion.nl 185.233.173.150NOERROR, 11 ms, authoritativenoyes / yesrefused-
nsauth1.cyberfusion.nl 2a0c:eb00:0:f10:185:233:173:150NOERROR, 17 ms, authoritativenoyes / yesrefused-
nsauth2.cyberfusion.nu 149.210.201.179NOERROR, 12 ms, authoritativenoyes / yesrefused-
nsauth2.cyberfusion.nu 2a01:7c8:aab8:81:5054:ff:fec4:9ca8NOERROR, 12 ms, authoritativenoyes / yesrefused-

Checks

  • ✓ All respond #14
    All 6 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

pass

serial 2026102201 · primary nsauth0.cyberfusion.nl

Found

Primary (MNAME)
nsauth0.cyberfusion.nl
Contact (RNAME)
hostmaster.cyberfusion.nl
Serial
2026102201
Refresh / retry
14400 s / 3600 s
Expire
604800 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
nsauth0.cyberfusion.nl (185.233.173.153)2026102201
nsauth0.cyberfusion.nl (2a0c:eb00:0:f10:185:233:173:153)2026102201
nsauth1.cyberfusion.nl (185.233.173.150)2026102201
nsauth1.cyberfusion.nl (2a0c:eb00:0:f10:185:233:173:150)2026102201
nsauth2.cyberfusion.nu (149.210.201.179)2026102201
nsauth2.cyberfusion.nu (2a01:7c8:aab8:81:5054:ff:fec4:9ca8)2026102201

Checks

  • ✓ Serial 2026102201 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 4h, retry 1h, expire 7d, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver nsauth0.cyberfusion.nl is one of the listed nameservers.
  • ✓ Contact hostmaster@cyberfusion.nl #25
    The SOA RNAME hostmaster.cyberfusion.nl means hostmaster@cyberfusion.nl.
  • ✓ Date-based serial #26
    The serial 2026102201 follows the YYYYMMDDnn convention (2026-10-22).

DNSSEC

info

Signed, DS published at parent

Found

Validated by resolver
yes
Denial of existence
NSEC
Signatures valid until
5 November 2026

DS at the parent

Key tagAlgorithmDigestMatches a key
48811ECDSAP256SHA256 (13)SHA256 2AA6501956A57E91…yes

DNSKEY in the zone

Key tagRoleAlgorithm
48811KSK (257)ECDSAP256SHA256 (13)

Checks

  • ✓ Signed and validated #27
    The zone is signed, the parent publishes a DS record, and the resolver validates the answers.
  • ✓ DS matches a key #28
    The DS record at the parent matches a key in the zone: key tag 48811 (SHA256).
  • ✓ Modern algorithms #29
    Key algorithms: ECDSAP256SHA256 (13).
  • ✓ Signatures valid until 2026-11-05 #30
    The earliest DNSKEY/SOA signature expires at 2026-11-05 00:00 UTC.
  • i
    NSEC
    The zone uses NSEC, so its full contents can be listed by walking the NSEC chain. That is fine unless the names are sensitive.
    #31

Records

pass

15 records at the apex

Found

Read from
185.233.173.153:53
TypeValueTTL
SOAnsauth0.cyberfusion.nl. hostmaster.cyberfusion.nl. 2026102201 14400 3600 604800 36003600
NSnsauth0.cyberfusion.nl.3600
NSnsauth1.cyberfusion.nl.3600
NSnsauth2.cyberfusion.nu.3600
A185.233.175.236300
AAAA2a0c:eb00:0:f7::27300
MX1 smtp.google.com.300
TXT"klaviyo-site-verification=WqPJSY"3600
TXT"google-site-verification=o22qA0rERwl3y3xv0jhVTm_mbc7Ex1NFnp_zt9pCEQY"3600
TXT"v=spf1 include:_spf.cyberfusion.nl _spf.google.com include:klaviyo.com ~all"3600
CAA0 issue "sectigo.com"3600
CAA0 issuewild "letsencrypt.org"3600
CAA0 issue "letsencrypt.org"3600
CAA0 issuewild "sectigo.com"3600
CAA0 iodef "mailto:customer-domains@cyberfusion.nl"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 5m, AAAA 5m, MX 5m, NS 1h.
  • ✓ No CNAME at the apex #33
    The zone apex has no CNAME record.
  • ✓ No wildcard #34
    Names that don't exist return NXDOMAIN.
  • ✓ CAA restricts issuance #35
    Certificates may be issued by: sectigo.com, letsencrypt.org.