Domain report: concertgebouw.nl

Registration

info

.nl country-code

Found

TLD: .nl (country-code)
ICANN policies apply: no

Lookup error: https://rdap.sidn.nl/domain/concertgebouw.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/concertgebouw.nl returned HTTP 429

#3

Delegation

info

ns1.dn-s.nl, ns2.dn-s.nl, ns3.dn-s.nl, ns4.dn-s.nl

Found

Parent zone: nl
Delegation from: ns1.dns.nl (194.0.28.53)
NS at the parent: ns1.dn-s.nl, ns2.dn-s.nl, ns3.dn-s.nl, ns4.dn-s.nl
NS in the zone: ns1.dn-s.nl, ns2.dn-s.nl, ns3.dn-s.nl, ns4.dn-s.nl

Nameserver	Addresses	Network (AS)	Glue
ns1.dn-s.nl	185.104.28.19 2a06:2ec0:1::10	AS206281 AS-ZXCS - Stichting DIGI NL, NL AS206281 AS-ZXCS - Stichting DIGI NL, NL	-
ns2.dn-s.nl	46.101.179.64 2a03:b0c0:3:d0::116:2001	AS14061 DIGITALOCEAN-ASN - DigitalOcean, LLC, US AS14061 DIGITALOCEAN-ASN - DigitalOcean, LLC, US	-
ns3.dn-s.nl	178.62.208.8 2a03:b0c0:2:d0::57:1001	AS14061 DIGITALOCEAN-ASN - DigitalOcean, LLC, US AS14061 DIGITALOCEAN-ASN - DigitalOcean, LLC, US	-
ns4.dn-s.nl	185.220.172.14 2a06:2ec0:1:a::d53	AS206281 AS-ZXCS - Stichting DIGI NL, NL AS206281 AS-ZXCS - Stichting DIGI NL, NL	-

Checks

✓ 4 nameservers #6

Delegated to ns1.dn-s.nl, ns2.dn-s.nl, ns3.dn-s.nl, ns4.dn-s.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 3 IPv6 /48s.
✓ 2 autonomous systems #11

The nameservers are spread over: AS14061 (DIGITALOCEAN-ASN - DigitalOcean, LLC, US): 4 addresses; AS206281 (AS-ZXCS - Stichting DIGI NL, NL): 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

info

8 of 8 addresses answer authoritatively

Found

Nameserver	Answer	Recursion	TCP / EDNS	AXFR	Version
ns1.dn-s.nl 185.104.28.19	NOERROR, 10 ms, authoritative	no	yes / yes	refused	Unknown
ns1.dn-s.nl 2a06:2ec0:1::10	NOERROR, 11 ms, authoritative	no	yes / yes	refused	Unknown
ns2.dn-s.nl 46.101.179.64	NOERROR, 18 ms, authoritative	no	yes / yes	refused	Unknown
ns2.dn-s.nl 2a03:b0c0:3:d0::116:2001	NOERROR, 18 ms, authoritative	no	yes / yes	refused	Unknown
ns3.dn-s.nl 178.62.208.8	NOERROR, 15 ms, authoritative	no	yes / yes	refused	Unknown
ns3.dn-s.nl 2a03:b0c0:2:d0::57:1001	NOERROR, 11 ms, authoritative	no	yes / yes	refused	Unknown
ns4.dn-s.nl 185.220.172.14	NOERROR, 10 ms, authoritative	no	yes / yes	refused	Unknown
ns4.dn-s.nl 2a06:2ec0:1:a::d53	NOERROR, 10 ms, authoritative	no	yes / yes	refused	Unknown

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.dn-s.nl: "Unknown"; ns2.dn-s.nl: "Unknown"; ns3.dn-s.nl: "Unknown"; ns4.dn-s.nl: "Unknown".

#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

warn

serial 2026100601 · primary ns1.dn-s.nl

Found

Primary (MNAME): ns1.dn-s.nl
Contact (RNAME): hostmaster.concertgebouw.nl
Serial: 2026100601
Refresh / retry: 600 s / 3600 s
Expire: 1209600 s
Negative TTL: 86400 s

Serial per nameserver

Nameserver	Serial
ns1.dn-s.nl (185.104.28.19)	2026100601
ns1.dn-s.nl (2a06:2ec0:1::10)	2026100601
ns2.dn-s.nl (46.101.179.64)	2026100601
ns2.dn-s.nl (2a03:b0c0:3:d0::116:2001)	2026100601
ns3.dn-s.nl (178.62.208.8)	2026100601
ns3.dn-s.nl (2a03:b0c0:2:d0::57:1001)	2026100601
ns4.dn-s.nl (185.220.172.14)	2026100601
ns4.dn-s.nl (2a06:2ec0:1:a::d53)	2026100601

Checks

✓ Serial 2026100601 everywhere #22

All nameservers serve the same version of the zone.
!

Unusual SOA timers

refresh 10m is outside 20m–1d; retry 1h should be shorter than refresh 10m. Current values: refresh 10m, retry 1h, expire 14d, negative TTL 1d.

#23
✓ Primary is a public nameserver #24

The primary nameserver ns1.dn-s.nl is one of the listed nameservers.
✓ Contact hostmaster@concertgebouw.nl #25

The SOA RNAME hostmaster.concertgebouw.nl means hostmaster@concertgebouw.nl.
✓ Date-based serial #26

The serial 2026100601 follows the YYYYMMDDnn convention (2026-10-06).

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 tag	Algorithm	Digest	Matches a key
44347	RSASHA256 (8)	SHA256 BBB91344FA9B69FC…	yes

DNSKEY in the zone

Key tag	Role	Algorithm
44347	KSK (257)	RSASHA256 (8)

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 44347 (SHA256).
✓ Modern algorithms #29

Key algorithms: RSASHA256 (8).
✓ 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

23 records at the apex

Found

Read from: 185.104.28.19:53

Type	Value	TTL
SOA	ns1.dn-s.nl. hostmaster.concertgebouw.nl. 2026100601 600 3600 1209600 86400	86400
NS	ns4.dn-s.nl.	600
NS	ns1.dn-s.nl.	600
NS	ns2.dn-s.nl.	600
NS	ns3.dn-s.nl.	600
A	178.22.63.31	600
MX	10 concertgebouw-nl.mail.protection.outlook.com.	600
TXT	"DomainVerification=SFGR57CTQ0KGEAYN4D7PLJNDMQHZ8XL0XAH7CRKADTPQC6L7WM6PO1X9995R3WWL"	600
TXT	"RQPAttxTGTqMDFF9JPOmAJFgmjphPBYfHbP1LxBBzXiTe6URHHtd/dtDyEUunnF05CN4+WFqb0eidAwz/gY78g=="	600
TXT	"google-site-verification=V9KyLf-lZ1T2wX3PSl_e5E90Q7TMzw3dlzGggx1TfPc"	600
TXT	"facebook-domain-verification=eg1dejt5xjz6ensille3pn5t30c0tq"	600
TXT	"google-site-verification=xqz1tVDuc5Gs_S-KLivQb3CVR3yITgJxw4ChgGKJhik"	600
TXT	"v=spf1 redirect=_sog58p08n.sdmarc.net"	600
CAA	0 issue "amazon.com"	600
CAA	0 issue "amazontrust.com"	600
CAA	0 issue "letsencrypt.org"	600
CAA	0 issue "awstrust.com"	600
CAA	0 iodef "mailto:support@concertgebouw.nl"	600
CAA	0 issue "amazonaws.com"	600
CAA	0 issue "digicert.com"	600
CAA	0 issue "sectigo.com"	600
CAA	0 issuewild "sectigo.com"	600
CAA	0 issuewild "letsencrypt.org"	600

Checks

✓ TTLs within range #32

TTLs: A 10m, MX 10m, NS 10m. The NS TTL at the parent is 1h and in the zone 10m; 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, amazontrust.com, letsencrypt.org, awstrust.com, amazonaws.com, digicert.com, sectigo.com.