sdu.nl

Checked 21 October 2026, 21:25 UTC · via 8.8.8.8
!Passed with warnings
25 passed 1 warning 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/sdu.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/sdu.nl returned HTTP 429
    #3

Delegation

info

ns-1016.awsdns-63.net, ns-1511.awsdns-60.org, ns-17.awsdns-02.com, ns-1991.awsdns-56.co.uk

Found

Parent zone
nl
Delegation from
ns1.dns.nl (194.0.28.53)
NS at the parent
ns-1016.awsdns-63.net, ns-1511.awsdns-60.org, ns-17.awsdns-02.com, ns-1991.awsdns-56.co.uk
NS in the zone
ns-1016.awsdns-63.net, ns-1511.awsdns-60.org, ns-17.awsdns-02.com, ns-1991.awsdns-56.co.uk
NameserverAddressesNetwork (AS)Glue
ns-1016.awsdns-63.net205.251.195.248 2600:9000:5303:f800::1AS16509 AMAZON-02 - Amazon.com, Inc., US AS16509 AMAZON-02 - Amazon.com, Inc., US-
ns-1511.awsdns-60.org205.251.197.231 2600:9000:5305:e700::1AS16509 AMAZON-02 - Amazon.com, Inc., US AS16509 AMAZON-02 - Amazon.com, Inc., US-
ns-17.awsdns-02.com205.251.192.17 2600:9000:5300:1100::1AS16509 AMAZON-02 - Amazon.com, Inc., US AS16509 AMAZON-02 - Amazon.com, Inc., US-
ns-1991.awsdns-56.co.uk205.251.199.199 2600:9000:5307:c700::1AS16509 AMAZON-02 - Amazon.com, Inc., US AS16509 AMAZON-02 - Amazon.com, Inc., US-

Checks

  • ✓ 4 nameservers #6
    Delegated to ns-1016.awsdns-63.net, ns-1511.awsdns-60.org, ns-17.awsdns-02.com, ns-1991.awsdns-56.co.uk.
  • ✓ 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.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS16509 (AMAZON-02 - Amazon.com, Inc., US): 8 addresses). An outage or attack on that network affects all nameservers; large anycast providers mitigate this, but a secondary DNS provider adds independence.
    #11
  • ✓ Nameserver names under 4 TLDs #12
    Nameserver names use the TLDs .com, .net, .org, .uk.
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

pass

8 of 8 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns-1016.awsdns-63.net 205.251.195.248NOERROR, 4 ms, authoritativenoyes / yesrefused-
ns-1016.awsdns-63.net 2600:9000:5303:f800::1NOERROR, 4 ms, authoritativenoyes / yesrefused-
ns-1511.awsdns-60.org 205.251.197.231NOERROR, 3 ms, authoritativenoyes / yesrefused-
ns-1511.awsdns-60.org 2600:9000:5305:e700::1NOERROR, 4 ms, authoritativenoyes / yesrefused-
ns-17.awsdns-02.com 205.251.192.17NOERROR, 9 ms, authoritativenoyes / yesrefused-
ns-17.awsdns-02.com 2600:9000:5300:1100::1NOERROR, 9 ms, authoritativenoyes / yesrefused-
ns-1991.awsdns-56.co.uk 205.251.199.199NOERROR, 9 ms, authoritativenoyes / yesrefused-
ns-1991.awsdns-56.co.uk 2600:9000:5307:c700::1NOERROR, 9 ms, authoritativenoyes / yesrefused-

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.
  • ✓ 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 1 · primary ns-1511.awsdns-60.org

Found

Primary (MNAME)
ns-1511.awsdns-60.org
Contact (RNAME)
awsdns-hostmaster.amazon.com
Serial
1
Refresh / retry
7200 s / 900 s
Expire
1209600 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
ns-1016.awsdns-63.net (205.251.195.248)1
ns-1016.awsdns-63.net (2600:9000:5303:f800::1)1
ns-1511.awsdns-60.org (205.251.197.231)1
ns-1511.awsdns-60.org (2600:9000:5305:e700::1)1
ns-17.awsdns-02.com (205.251.192.17)1
ns-17.awsdns-02.com (2600:9000:5300:1100::1)1
ns-1991.awsdns-56.co.uk (205.251.199.199)1
ns-1991.awsdns-56.co.uk (2600:9000:5307:c700::1)1

Checks

  • ✓ Serial 1 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 2h, retry 15m, expire 14d, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns-1511.awsdns-60.org is one of the listed nameservers.
  • ✓ Contact awsdns-hostmaster@amazon.com #25
    The SOA RNAME awsdns-hostmaster.amazon.com means awsdns-hostmaster@amazon.com.
  • ✓ Counter serial #26
    The serial 1 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

pass

31 records at the apex

Found

Read from
205.251.195.248:53
TypeValueTTL
SOAns-1511.awsdns-60.org. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400900
NSns-1016.awsdns-63.net.172800
NSns-1511.awsdns-60.org.172800
NSns-17.awsdns-02.com.172800
NSns-1991.awsdns-56.co.uk.172800
A54.73.42.208300
MX10 mxb-001cc301.gslb.pphosted.com.14400
MX5 mxa-001cc301.gslb.pphosted.com.14400
TXT"MS=ms29415470"3600
TXT"_globalsign-domain-verification=nI5rN-xsYKheqKEaj39sKSu7EnU0AvM25CFEVMSPrY"3600
TXT"_globalsign-domain-verification=qb_JES4TI9_3ANlOGQjNnCCNkd214BR9ZI0UE9zgJs"3600
TXT"amazonses: 4WYSwlAEApZ2Gqhn9nlZ7yXmaH5P2kYH7fLBcRs14oo ="3600
TXT"apple-domain-verification=AasrKj2qM6ce7dhq"3600
TXT"atlassian-domain-verification=okFYucKODLTepKdprWwOaWaCFYdO77W47Qb/2NWgnVbA51gWxzvMNPyyZBNMzv1E"3600
TXT"atlassian-sending-domain-verification=6818225e-3e8f-41d8-996f-a2d3bc42a55c"3600
TXT"facebook-domain-verification=fqonh1wo9cgtwiex3afa4rm2o8a0wd"3600
TXT"fv53mn5dc44htql1k8v157z794v2h1v9"3600
TXT"google-site-verification=sFFo8Xg0EzadBP-jYGs-wzZKMWTALvikFJjgaQY6Hlg"3600
TXT"google-site-verification=sGZy7g9-D0CZxyZRrIewOpVHTm03alcCrfRoV7_M9Cw"3600
TXT"jj7f576lhvffn7t466y3cz0nzprtn1l9"3600
TXT"openai-domain-verification=dv-0cTCOh4hmzwe9s6nkR9ETCTC"3600
TXT"pardot1095762=096a048fa2454faf2fd4427e10fc53613d453c1dd6c5f14b49c9cb9c8974c82d"3600
TXT"v=spf1 include:spf.protection.outlook.com include:spf.autopilothq.com include:spf.afas.online -all"3600
CAA0 iodef "mailto:abuse@sdu.nl"3600
CAA0 issue "amazon.com"3600
CAA0 issue "digicert.com"3600
CAA0 issue "letsencrypt.org"3600
CAA0 issue "pki.goog"3600
CAA0 issue "sectigo.com"3600
CAA0 issuewild "amazon.com"3600
CAA0 issuewild "letsencrypt.org"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 5m, MX 4h, NS 2d. The NS TTL at the parent is 1h and in the zone 2d; 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.
  • ✓ CAA restricts issuance #35
    Certificates may be issued by: amazon.com, digicert.com, letsencrypt.org, pki.goog, sectigo.com.