onlineagenda.nl

Checked 22 October 2026, 15:01 UTC · via 8.8.8.8
✗Problems found
19 passed 3 warnings 1 failed 6 info

Registration

info

.nl country-code

Found

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

Delegation

warn

ns1.plazaxl-server2.nl, ns2.plazaxl-server2.nl

Found

Parent zone
nl
Delegation from
ns1.dns.nl (194.0.28.53)
NS at the parent
ns1.plazaxl-server2.nl, ns2.plazaxl-server2.nl
NS in the zone
ns0.mailhet.nu, ns1.mailhet.nu
NameserverAddressesNetwork (AS)Glue
ns0.mailhet.nu (zone only)87.253.149.136 2a01:7c8:bb02:3a8:5054:ff:fe98:67e5AS20857 TRANSIP-AS - Signet B.V., NL AS20857 TRANSIP-AS - Signet B.V., NL-
ns1.mailhet.nu (zone only)87.106.133.29 2a01:239:290:ab00::1AS8560 IONOS-AS - IONOS SE, DE AS8560 IONOS-AS - IONOS SE, DE-
ns1.plazaxl-server2.nl (parent only)87.253.149.136 2a01:7c8:bb02:3a8:5054:ff:fe98:67e5AS20857 TRANSIP-AS - Signet B.V., NL AS20857 TRANSIP-AS - Signet B.V., NL-
ns2.plazaxl-server2.nl (parent only)87.106.133.29 2a01:239:290:ab00::1AS8560 IONOS-AS - IONOS SE, DE AS8560 IONOS-AS - IONOS SE, DE-

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: ns1.plazaxl-server2.nl, ns2.plazaxl-server2.nl.
    #6
  • !
    NS sets differ
    The nameservers at the parent and in the zone should be the same. Only at the parent: ns1.plazaxl-server2.nl, ns2.plazaxl-server2.nl; only in the zone: ns0.mailhet.nu, ns1.mailhet.nu. ns0.mailhet.nu, ns1.mailhet.nu, ns1.plazaxl-server2.nl, ns2.plazaxl-server2.nl report NS ns0.mailhet.nu ns1.mailhet.nu.
    #7
  • ✓ 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: AS20857 (TRANSIP-AS - Signet B.V., NL): 4 addresses; AS8560 (IONOS-AS - IONOS SE, DE): 4 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

fail

8 of 8 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns0.mailhet.nu 87.253.149.136NOERROR, 11 ms, authoritativenoyes / yesrefusednone
ns0.mailhet.nu 2a01:7c8:bb02:3a8:5054:ff:fe98:67e5NOERROR, 13 ms, authoritativenoyes / yesrefusednone
ns1.mailhet.nu 87.106.133.29NOERROR, 13 ms, authoritativenoyes / yesALLOWED (29 records)9.18.39-0ubuntu0.24.04.8-Ubuntu
ns1.mailhet.nu 2a01:239:290:ab00::1NOERROR, 13 ms, authoritativenoyes / yesALLOWED (29 records)9.18.39-0ubuntu0.24.04.8-Ubuntu
ns1.plazaxl-server2.nl 87.253.149.136NOERROR, 10 ms, authoritativenoyes / yesrefusednone
ns1.plazaxl-server2.nl 2a01:7c8:bb02:3a8:5054:ff:fe98:67e5NOERROR, 11 ms, authoritativenoyes / yesrefusednone
ns2.plazaxl-server2.nl 87.106.133.29NOERROR, 13 ms, authoritativenoyes / yesALLOWED (29 records)9.18.39-0ubuntu0.24.04.8-Ubuntu
ns2.plazaxl-server2.nl 2a01:239:290:ab00::1NOERROR, 13 ms, authoritativenoyes / yesALLOWED (29 records)9.18.39-0ubuntu0.24.04.8-Ubuntu

Checks

  • ✓ All respond #14
    All 8 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: ns1.mailhet.nu: "9.18.39-0ubuntu0.24.04.8-Ubuntu"; ns2.plazaxl-server2.nl: "9.18.39-0ubuntu0.24.04.8-Ubuntu". Hide or replace the version string.
    #17
  • ✗
    Zone transfer allowed
    These nameservers send the complete zone to anyone who asks (AXFR), exposing all host names: ns1.mailhet.nu (87.106.133.29): 29 records; ns1.mailhet.nu (2a01:239:290:ab00::1): 29 records; ns2.plazaxl-server2.nl (87.106.133.29): 29 records; ns2.plazaxl-server2.nl (2a01:239:290:ab00::1): 29 records. Restrict zone transfers to your secondary servers.
    #18
  • ✓ 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 2026090603 · primary ns0.mailhet.nu

Found

Primary (MNAME)
ns0.mailhet.nu
Contact (RNAME)
ssl.plazaxl.nl
Serial
2026090603
Refresh / retry
10800 s / 3600 s
Expire
1209600 s
Negative TTL
10800 s

Serial per nameserver

NameserverSerial
ns0.mailhet.nu (87.253.149.136)2026090603
ns0.mailhet.nu (2a01:7c8:bb02:3a8:5054:ff:fe98:67e5)2026090603
ns1.mailhet.nu (87.106.133.29)2026090603
ns1.mailhet.nu (2a01:239:290:ab00::1)2026090603
ns1.plazaxl-server2.nl (87.253.149.136)2026090603
ns1.plazaxl-server2.nl (2a01:7c8:bb02:3a8:5054:ff:fe98:67e5)2026090603
ns2.plazaxl-server2.nl (87.106.133.29)2026090603
ns2.plazaxl-server2.nl (2a01:239:290:ab00::1)2026090603

Checks

  • ✓ Serial 2026090603 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 3h, retry 1h, expire 14d, negative TTL 3h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns0.mailhet.nu is one of the listed nameservers.
  • ✓ Contact ssl@plazaxl.nl #25
    The SOA RNAME ssl.plazaxl.nl means ssl@plazaxl.nl.
  • ✓ Date-based serial #26
    The serial 2026090603 follows the YYYYMMDDnn convention (2026-09-06).

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

8 records at the apex

Found

Read from
87.253.149.136:53
TypeValueTTL
SOAns0.mailhet.nu. ssl.plazaxl.nl. 2026090603 10800 3600 1209600 1080014400
NSns0.mailhet.nu.14400
NSns1.mailhet.nu.14400
A87.253.149.13614400
AAAA2a01:7c8:bb02:3a8:5054:ff:fe98:67e514400
MX10 mail.onlineagenda.nl.14400
TXT"google-site-verification=Clsp4eXtiV2rThuBX5ZXShVn77Kcf54Ppiy7I5LnTU8"14400
TXT"v=spf1 mx a include:_spf.plazaxl.nl -all"14400

Checks

  • ✓ TTLs within range #32
    TTLs: A 4h, AAAA 4h, MX 4h, NS 4h. The NS TTL at the parent is 1h and in the zone 4h; resolvers may use either.
  • ✓ No CNAME at the apex #33
    The zone apex has no CNAME record.
  • i
    Wildcard record
    A random name under the zone resolves, so there is a wildcard (*) record. Typos and non-existent hosts resolve too, which can confuse mail and certificate checks.
    #34
  • 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