zlto.nl

Checked 22 October 2026, 17:30 UTC · via 8.8.8.8
!Passed with warnings
26 passed 1 warning 0 failed 6 info

Registration

info

.nl country-code

Found

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

Delegation

info

ns1.agroweb.nl, ns2.agroweb.nl, ns3.agroweb.nl

Found

Parent zone
nl
Delegation from
ns1.dns.nl (194.0.28.53)
NS at the parent
ns1.agroweb.nl, ns2.agroweb.nl, ns3.agroweb.nl
NS in the zone
ns1.agroweb.nl, ns2.agroweb.nl, ns3.agroweb.nl
NameserverAddressesNetwork (AS)Glue
ns1.agroweb.nl5.255.75.20 2a00:1ca8:1f:56::20AS50673 Serverius-as - Serverius Holding B.V., NL AS50673 Serverius-as - Serverius Holding B.V., NL5.255.75.20 2a00:1ca8:1f:56::20
ns2.agroweb.nl5.255.75.21 2a00:1ca8:1f:56::21AS50673 Serverius-as - Serverius Holding B.V., NL AS50673 Serverius-as - Serverius Holding B.V., NL5.255.75.21 2a00:1ca8:1f:56::21
ns3.agroweb.nl5.178.64.93 2a03:3f40:d:67::23AS50673 Serverius-as - Serverius Holding B.V., NL AS50673 Serverius-as - Serverius Holding B.V., NL5.178.64.93 2a03:3f40:d:67::23

Checks

  • ✓ 3 nameservers #6
    Delegated to ns1.agroweb.nl, ns2.agroweb.nl, ns3.agroweb.nl.
  • ✓ 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.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS50673 (Serverius-as - Serverius Holding B.V., NL): 6 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
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

warn

6 of 6 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns1.agroweb.nl 5.255.75.20NOERROR, 11 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.9.18 (built Oct 7 2026 06:26:09 by root@localhost)
ns1.agroweb.nl 2a00:1ca8:1f:56::20NOERROR, 12 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.9.18 (built Oct 7 2026 06:26:09 by root@localhost)
ns2.agroweb.nl 5.255.75.21NOERROR, 10 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.9.18 (built Oct 7 2026 06:26:09 by root@localhost)
ns2.agroweb.nl 2a00:1ca8:1f:56::21NOERROR, 11 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.9.18 (built Oct 7 2026 06:26:09 by root@localhost)
ns3.agroweb.nl 5.178.64.93NOERROR, 13 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.9.18 (built Oct 7 2026 06:26:09 by root@localhost)
ns3.agroweb.nl 2a03:3f40:d:67::23NOERROR, 13 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.9.18 (built Oct 7 2026 06:26:09 by root@localhost)

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.
  • !
    Software version disclosed
    These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: ns1.agroweb.nl: "PowerDNS Authoritative Server 4.9.18 (built Oct 7 2026 06:26:09 by root@localhost)"; ns2.agroweb.nl: "PowerDNS Authoritative Server 4.9.18 (built Oct 7 2026 06:26:09 by root@localhost)"; ns3.agroweb.nl: "PowerDNS Authoritative Server 4.9.18 (built Oct 7 2026 06:26:09 by root@localhost)". 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.

SOA

pass

serial 2026072566 · primary ns1.agroweb.nl

Found

Primary (MNAME)
ns1.agroweb.nl
Contact (RNAME)
postmaster.zlto.nl
Serial
2026072566
Refresh / retry
28800 s / 7200 s
Expire
604800 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
ns1.agroweb.nl (5.255.75.20)2026072566
ns1.agroweb.nl (2a00:1ca8:1f:56::20)2026072566
ns2.agroweb.nl (5.255.75.21)2026072566
ns2.agroweb.nl (2a00:1ca8:1f:56::21)2026072566
ns3.agroweb.nl (5.178.64.93)2026072566
ns3.agroweb.nl (2a03:3f40:d:67::23)2026072566

Checks

  • ✓ Serial 2026072566 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 8h, retry 2h, expire 7d, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns1.agroweb.nl is one of the listed nameservers.
  • ✓ Contact postmaster@zlto.nl #25
    The SOA RNAME postmaster.zlto.nl means postmaster@zlto.nl.
  • ✓ Date-based serial #26
    The serial 2026072566 follows the YYYYMMDDnn convention (2026-07-25).

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
23661ECDSAP256SHA256 (13)SHA256 98E01F079E83EA43…yes

DNSKEY in the zone

Key tagRoleAlgorithm
23661KSK (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 23661 (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

info

11 records at the apex

Found

Read from
5.255.75.20:53
TypeValueTTL
SOAns1.agroweb.nl. postmaster.zlto.nl. 2026072566 28800 7200 604800 360086400
NSns2.agroweb.nl.86400
NSns3.agroweb.nl.86400
NSns1.agroweb.nl.86400
A87.233.198.116600
AAAA2001:9a8:a6:0:87:233:198:116600
MX0 zlto-nl.mail.protection.outlook.com.3600
TXT"hXSLeGD7TpKL4d2gfWVtO6zxgPWnVH2eDDUSaSH5qiKsMDiigJlyJqfwN3rEDycTXmU18DoNc4y1r97xoXGQaA=="3600
TXT"v=spf1 include:spf.protection.outlook.com include:_spf.onlinespamfilter.nl ip4:5.255.75.0/24 include:spf.zlto.nl include:_spf.spotler.email include:spf.tribecrm.nl -all"3600
TXT"apple-domain-verification=QY0PgKTw6TLMigTm"3600
TXT"MS=ms51397653"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 10m, AAAA 10m, MX 1h, 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