knaw.nl

Checked 21 October 2026, 21:22 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/knaw.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/knaw.nl returned HTTP 429
    #3

Delegation

pass

ns1.surfnet.nl, ns1.zurich.surf.net, ns2.surfnet.nl, ns3.surfnet.nl

Found

Parent zone
nl
Delegation from
ns1.dns.nl (194.0.28.53)
NS at the parent
ns1.surfnet.nl, ns1.zurich.surf.net, ns2.surfnet.nl, ns3.surfnet.nl
NS in the zone
ns1.surfnet.nl, ns1.zurich.surf.net, ns2.surfnet.nl, ns3.surfnet.nl
NameserverAddressesNetwork (AS)Glue
ns1.surfnet.nl192.87.106.101 2001:610:1:800a:192:87:106:101AS1103 SURFNET-NL - SURF B.V., NL AS1103 SURFNET-NL - SURF B.V., NL192.87.106.101 2001:610:1:800a:192:87:106:101
ns1.zurich.surf.net195.176.255.9 2001:620:0:9::1103AS559 Switch - SWITCH, CH AS559 Switch - SWITCH, CH-
ns2.surfnet.nl192.87.36.2 2001:610:3:200a:192:87:36:2AS1103 SURFNET-NL - SURF B.V., NL AS1103 SURFNET-NL - SURF B.V., NL192.87.36.2 2001:610:3:200a:192:87:36:2
ns3.surfnet.nl195.169.124.71 2001:610:0:800c:195:169:124:71AS1103 SURFNET-NL - SURF B.V., NL AS1103 SURFNET-NL - SURF B.V., NL195.169.124.71 2001:610:0:800c:195:169:124:71

Checks

  • ✓ 4 nameservers #6
    Delegated to ns1.surfnet.nl, ns1.zurich.surf.net, ns2.surfnet.nl, ns3.surfnet.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 4 IPv4 /24s and 4 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS1103 (SURFNET-NL - SURF B.V., NL): 6 addresses; AS559 (Switch - SWITCH, CH): 2 addresses.
  • ✓ Nameserver names under 2 TLDs #12
    Nameserver names use the TLDs .net, .nl.
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

info

8 of 8 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns1.surfnet.nl 192.87.106.101NOERROR, 9 ms, authoritativenoyes / yesrefusedThis is a SURFnet nameserver - dns-beheer@surfnet.nl
ns1.surfnet.nl 2001:610:1:800a:192:87:106:101NOERROR, 9 ms, authoritativenoyes / yesrefusedThis is a SURFnet nameserver - dns-beheer@surfnet.nl
ns1.zurich.surf.net 195.176.255.9NOERROR, 10 ms, authoritativenoyes / yesrefusedThis is a SURFnet nameserver - dns-beheer@surf.nl
ns1.zurich.surf.net 2001:620:0:9::1103NOERROR, 9 ms, authoritativenoyes / yesrefusedThis is a SURFnet nameserver - dns-beheer@surf.nl
ns2.surfnet.nl 192.87.36.2NOERROR, 12 ms, authoritativenoyes / yesrefusedThis is a SURFnet nameserver - dns-beheer@surfnet.nl
ns2.surfnet.nl 2001:610:3:200a:192:87:36:2NOERROR, 12 ms, authoritativenoyes / yesrefusedThis is a SURFnet nameserver - dns-beheer@surfnet.nl
ns3.surfnet.nl 195.169.124.71NOERROR, 10 ms, authoritativenoyes / yesrefusedThis is a SURFnet nameserver - dns-beheer@surfnet.nl
ns3.surfnet.nl 2001:610:0:800c:195:169:124:71NOERROR, 10 ms, authoritativenoyes / yesrefusedThis is a SURFnet nameserver - dns-beheer@surfnet.nl

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.
  • i
    Identifying string disclosed
    These nameservers answer version queries with a string that is not a version number: ns1.surfnet.nl: "This is a SURFnet nameserver - dns-beheer@surfnet.nl"; ns1.zurich.surf.net: "This is a SURFnet nameserver - dns-beheer@surf.nl"; ns2.surfnet.nl: "This is a SURFnet nameserver - dns-beheer@surfnet.nl"; ns3.surfnet.nl: "This is a SURFnet nameserver - dns-beheer@surfnet.nl".
    #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 2026101501 · primary ns1.surfnet.nl

Found

Primary (MNAME)
ns1.surfnet.nl
Contact (RNAME)
dns-beheer.surf.nl
Serial
2026101501
Refresh / retry
10800 s / 3600 s
Expire
604800 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
ns1.surfnet.nl (192.87.106.101)2026101501
ns1.surfnet.nl (2001:610:1:800a:192:87:106:101)2026101501
ns1.zurich.surf.net (195.176.255.9)2026101501
ns1.zurich.surf.net (2001:620:0:9::1103)2026101501
ns2.surfnet.nl (192.87.36.2)2026101501
ns2.surfnet.nl (2001:610:3:200a:192:87:36:2)2026101501
ns3.surfnet.nl (195.169.124.71)2026101501
ns3.surfnet.nl (2001:610:0:800c:195:169:124:71)2026101501

Checks

  • ✓ Serial 2026101501 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 3h, retry 1h, expire 7d, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns1.surfnet.nl is one of the listed nameservers.
  • ✓ Contact dns-beheer@surf.nl #25
    The SOA RNAME dns-beheer.surf.nl means dns-beheer@surf.nl.
  • ✓ Date-based serial #26
    The serial 2026101501 follows the YYYYMMDDnn convention (2026-10-15).

DNSSEC

pass

Signed, DS published at parent

Found

Validated by resolver
yes
Denial of existence
NSEC3
NSEC3
0 iterations, 0-byte salt
Signatures valid until
29 October 2026

DS at the parent

Key tagAlgorithmDigestMatches a key
61177ECDSAP256SHA256 (13)SHA256 60DBB9E2AC8D467B…yes

DNSKEY in the zone

Key tagRoleAlgorithm
61177KSK (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 61177 (SHA256).
  • ✓ Modern algorithms #29
    Key algorithms: ECDSAP256SHA256 (13).
  • ✓ Signatures valid until 2026-10-29 #30
    The earliest DNSKEY/SOA signature expires at 2026-10-29 00:00 UTC.
  • ✓ NSEC3 as recommended #31
    The zone uses NSEC3 with 0 iterations and no salt (RFC 9276).

Records

pass

27 records at the apex

Found

Read from
192.87.106.101:53
TypeValueTTL
SOAns1.surfnet.nl. dns-beheer.surf.nl. 2026101501 10800 3600 604800 36003600
NSns1.zurich.surf.net.3600
NSns1.surfnet.nl.3600
NSns3.surfnet.nl.3600
NSns2.surfnet.nl.3600
A75.2.96.239300
A99.83.229.36300
AAAA2600:9000:a603:d4ab:3b46:6664:541:3b6c300
AAAA2600:9000:a715:397e:a2c2:110b:23d8:9a4f300
MX0 knaw-nl.mail.protection.outlook.com.300
TXT"bw=PyPBZFeE2tQkoeBRxXYmeBuS3uLfkdcUswjyyL973iS6"3600
TXT"apple-domain-verification=Kx3upsCHpUwCVztU"3600
TXT"procurios-site-verification=gagUhW73NFSdoza3Vaj3"3600
TXT"adobe-idp-site-verification=e574ceb69375114ec72f4bc11ec46141ec4c1c194117b84d37a333c9a1375d04"3600
TXT"have-i-been-pwned-verification=b1fd016e7cf47b73cf71b12f8ed10003"3600
TXT"google-site-verification=PA5clm1yBwUuQdkN5N0q_7xjZWXFMLR8nB2gLkVtX-A"3600
TXT"atlassian-domain-verification=9CeGC9xO7peuiHdqk16OTwnXaYfFs3iy9LGVIXxD/OxiJfEJahXbqX7Q5jrUrqJ2"3600
TXT"google-site-verification=HfgEEpjNWwaecSYe8KnNATWfrzAExHVBlvTsuA7kGnk"3600
TXT"HARICA-vvDQGK7pd3xxArhCoJD"3600
TXT"google-site-verification=94L39qL06lBH7le4wa74Yq2Me0ByOxWwLc7WdL8AA3s"3600
TXT"mCkVvXn6dUZyrFXWsGknbJGIaEbjWNeL3Rg2I92MbXPcArPmEMCPNv15sm0x65tcpO+jrI5Lt1gUi9X1EySVOw=="3600
TXT"v=spf1 include:spf.protection.outlook.com include:_spf.knaw.nl include:servers.mcsv.net ip4:5.39.185.32/29 ip4:185.181.140.187 ip4:87.253.234.71 ip4:87.253.234.73 ip4:87.253.234.85 include:spam1.htx.nl include:spf.mailjet.com include:_spf-dc55.sapsf.eu i" "nclude:spf.topdesk.net -all"3600
CAA0 issue "amazonaws.com"3600
CAA0 issue "harica.gr"3600
CAA0 issuewild "harica.gr"3600
CAA0 iodef "mailto:knawnet@knaw.nl"3600
CAA0 issue "letsencrypt.org"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: amazonaws.com, harica.gr, letsencrypt.org.