Domain report: csu.de

Registration

info

.de country-code

Found

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

Checks

i

.de 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

.de is delegated in the root zone and DNSSEC-signed.
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Registration data not available

No registration data via RDAP: the registry of .de offers no RDAP service. Many ccTLD registries don't offer RDAP; check the registry's WHOIS instead.

#3

Delegation

info

dns.noris.ch, dns.noris.de, dns.noris.net

Found

Parent zone: de
Delegation from: a.nic.de (194.0.0.53)
NS at the parent: dns.noris.ch, dns.noris.de, dns.noris.net
NS in the zone: dns.noris.ch, dns.noris.de, dns.noris.net

Nameserver	Addresses	Network (AS)	Glue
dns.noris.ch	194.31.2.65 2001:780:53d3::53	AS12337 NORIS-NETWORK - noris network AG, DE AS12337 NORIS-NETWORK - noris network AG, DE	-
dns.noris.de	192.109.102.65 2001:780:53d2::53	AS12337 NORIS-NETWORK - noris network AG, DE AS12337 NORIS-NETWORK - noris network AG, DE	192.109.102.65 2001:780:53d2::53
dns.noris.net	213.95.0.65 2001:780:53d1::53	AS12337 NORIS-NETWORK - noris network AG, DE AS12337 NORIS-NETWORK - noris network AG, DE	-

Checks

✓ 3 nameservers #6

Delegated to dns.noris.ch, dns.noris.de, dns.noris.net.
✓ 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 3 IPv4 /24s and 3 IPv6 /48s.
i

All nameservers in one AS

All nameserver addresses are announced by one network operator (AS12337 (NORIS-NETWORK - noris network AG, DE): 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
✓ Nameserver names under 3 TLDs #12

Nameserver names use the TLDs .ch, .de, .net.
✓ All reachable over IPv6 #13

Every nameserver has an IPv6 address.

Nameservers

pass

6 of 6 addresses answer authoritatively

Found

Nameserver	Answer	Recursion	TCP / EDNS	AXFR	Version
dns.noris.ch 194.31.2.65	NOERROR, 7 ms, authoritative	no	yes / yes	refused	-
dns.noris.ch 2001:780:53d3::53	NOERROR, 8 ms, authoritative	no	yes / yes	refused	-
dns.noris.de 192.109.102.65	NOERROR, 4 ms, authoritative	no	yes / yes	refused	-
dns.noris.de 2001:780:53d2::53	NOERROR, 4 ms, authoritative	no	yes / yes	refused	-
dns.noris.net 213.95.0.65	NOERROR, 4 ms, authoritative	no	yes / yes	refused	-
dns.noris.net 2001:780:53d1::53	NOERROR, 5 ms, authoritative	no	yes / yes	refused	-

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.
✓ 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

warn

serial 1791794508 · primary dns0.noris.net

Found

Primary (MNAME): dns0.noris.net
Contact (RNAME): hostmaster.noris.net
Serial: 1791794508
Refresh / retry: 86400 s / 86400 s
Expire: 2419200 s
Negative TTL: 600 s

Serial per nameserver

Nameserver	Serial
dns.noris.ch (194.31.2.65)	1791794508
dns.noris.ch (2001:780:53d3::53)	1791794508
dns.noris.de (192.109.102.65)	1791794508
dns.noris.de (2001:780:53d2::53)	1791794508
dns.noris.net (213.95.0.65)	1791794508
dns.noris.net (2001:780:53d1::53)	1791794508

Checks

✓ Serial 1791794508 everywhere #22

All nameservers serve the same version of the zone.
!

Unusual SOA timers

retry 1d should be shorter than refresh 1d. Current values: refresh 1d, retry 1d, expire 28d, negative TTL 10m.

#23
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Hidden master

The primary nameserver dns0.noris.net is not listed as a nameserver: a hidden master that only feeds the public secondaries. That is a common setup; make sure it is not reachable for zone transfers from outside.

#24
✓ Contact hostmaster@noris.net #25

The SOA RNAME hostmaster.noris.net means hostmaster@noris.net.
✓ Timestamp serial #26

The serial 1791794508 is a Unix timestamp (2026-10-12 08:41 UTC).

DNSSEC

info

Signed, DS published at parent

Found

Validated by resolver: yes
Denial of existence: NSEC3
NSEC3: 0 iterations, 0-byte salt
Signatures valid until: 11 November 2026

DS at the parent

Key tag	Algorithm	Digest	Matches a key
43211	RSASHA256 (8)	SHA256 A627E2B70C8F3956…	yes
28323	RSASHA256 (8)	SHA256 6B4415BB385E4394…	NO

DNSKEY in the zone

Key tag	Role	Algorithm
43211	KSK (257)	RSASHA256 (8)
34249	ZSK (256)	RSASHA256 (8)

Checks

✓ Signed and validated #27

The zone is signed, the parent publishes a DS record, and the resolver validates the answers.
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Unused DS records

These DS records match no key in the zone: key tag 28323 (SHA256). That is normal during a key rollover; otherwise remove them.

#28
✓ Modern algorithms #29

Key algorithms: RSASHA256 (8).
✓ Signatures valid until 2026-11-11 #30

The earliest DNSKEY/SOA signature expires at 2026-11-11 08:41 UTC.
✓ NSEC3 as recommended #31

The zone uses NSEC3 with 0 iterations and no salt (RFC 9276).

Records

info

10 records at the apex

Found

Read from: 194.31.2.65:53

Type	Value	TTL
SOA	dns0.noris.net. hostmaster.noris.net. 1791794508 86400 86400 2419200 600	86400
NS	dns.noris.ch.	86400
NS	dns.noris.de.	86400
NS	dns.noris.net.	86400
A	213.95.220.17	3600
MX	20 mx01.mucix.net.	3600
MX	10 mx00.csu.de.	3600
TXT	"_lsxrlmdr3yy5acuwkglvzcusqx6090z"	300
TXT	"_95ybw57qir23qyus7nov1aywbx8wryl"	300
TXT	"_hzmt416nctjpg2z0lirhz6ue64ldygo"	300

Checks

✓ TTLs within range #32

TTLs: A 1h, MX 1h, NS 1d.
✓ No CNAME at the apex #33

The zone apex has no CNAME record.
✓ No wildcard #34

Names that don't exist return NXDOMAIN.
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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