Domain report: mdc-berlin.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.
i

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

ns1.mdc-berlin.eu, ns2.mdc-berlin.eu, ns3.mdc-berlin.eu

Found

Parent zone: de
Delegation from: a.nic.de (194.0.0.53)
NS at the parent: ns1.mdc-berlin.eu, ns2.mdc-berlin.eu, ns3.mdc-berlin.eu
NS in the zone: ns1.mdc-berlin.eu, ns2.mdc-berlin.eu, ns3.mdc-berlin.eu

Nameserver	Addresses	Network (AS)	Glue
ns1.mdc-berlin.eu	141.80.181.237	AS210482 MDCBLN-AS - Max-Delbrueck-Centrum fuer Molekulare Medizin in der Helmholtz-Gemeinschaft, DE	-
ns2.mdc-berlin.eu	92.205.189.61 2a00:1169:110:3f10::	AS21499 GODADDY-SXB - Host Europe GmbH, DE AS21499 GODADDY-SXB - Host Europe GmbH, DE	-
ns3.mdc-berlin.eu	89.58.28.27 2a03:4000:63:d13:c8c9:c6ff:fed1:ef65	AS197540 netcup-AS - netcup GmbH, DE AS197540 netcup-AS - netcup GmbH, DE	-

Checks

✓ 3 nameservers #6

Delegated to ns1.mdc-berlin.eu, ns2.mdc-berlin.eu, ns3.mdc-berlin.eu.
✓ 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 2 IPv6 /48s.
✓ 3 autonomous systems #11

The nameservers are spread over: AS197540 (netcup-AS - netcup GmbH, DE): 2 addresses; AS210482 (MDCBLN-AS - Max-Delbrueck-Centrum fuer Molekulare Medizin in der Helmholtz-Gemeinschaft, DE): 1 address; AS21499 (GODADDY-SXB - Host Europe GmbH, DE): 2 addresses.
i

All nameserver names under .eu

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
i

Partly IPv6

These nameservers have no IPv6 address: ns1.mdc-berlin.eu.

#13

Nameservers

warn

5 of 5 addresses answer authoritatively

Found

Nameserver	Answer	Recursion	TCP / EDNS	AXFR	Version
ns1.mdc-berlin.eu 141.80.181.237	NOERROR, 12 ms, authoritative	no	yes / yes	refused	PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:11:18 by root@413bd54b27a2)
ns2.mdc-berlin.eu 92.205.189.61	NOERROR, 7 ms, authoritative	no	yes / yes	refused	-
ns2.mdc-berlin.eu 2a00:1169:110:3f10::	NOERROR, 7 ms, authoritative	no	yes / yes	refused	-
ns3.mdc-berlin.eu 89.58.28.27	NOERROR, 1 ms, authoritative	no	yes / yes	refused	PowerDNS Authoritative Server 4.9.11 (built Oct 15 2025 10:16:24 by root@localhost)
ns3.mdc-berlin.eu 2a03:4000:63:d13:c8c9:c6ff:fed1:ef65	NOERROR, 1 ms, authoritative	no	yes / yes	refused	PowerDNS Authoritative Server 4.9.11 (built Oct 15 2025 10:16:24 by root@localhost)

Checks

✓ All respond #14

All 5 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.mdc-berlin.eu: "PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:11:18 by root@413bd54b27a2)"; ns3.mdc-berlin.eu: "PowerDNS Authoritative Server 4.9.11 (built Oct 15 2025 10:16:24 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 2026102108 · primary ns1.mdc-berlin.eu

Found

Primary (MNAME): ns1.mdc-berlin.eu
Contact (RNAME): netz.mdc-berlin.de
Serial: 2026102108
Refresh / retry: 10800 s / 3600 s
Expire: 604800 s
Negative TTL: 43200 s

Serial per nameserver

Nameserver	Serial
ns1.mdc-berlin.eu (141.80.181.237)	2026102108
ns2.mdc-berlin.eu (92.205.189.61)	2026102108
ns2.mdc-berlin.eu (2a00:1169:110:3f10::)	2026102108
ns3.mdc-berlin.eu (89.58.28.27)	2026102108
ns3.mdc-berlin.eu (2a03:4000:63:d13:c8c9:c6ff:fed1:ef65)	2026102108

Checks

✓ Serial 2026102108 everywhere #22

All nameservers serve the same version of the zone.
✓ Timers within recommendations #23

SOA refresh 3h, retry 1h, expire 7d, negative TTL 12h.
✓ Primary is a public nameserver #24

The primary nameserver ns1.mdc-berlin.eu is one of the listed nameservers.
✓ Contact netz@mdc-berlin.de #25

The SOA RNAME netz.mdc-berlin.de means netz@mdc-berlin.de.
✓ Date-based serial #26

The serial 2026102108 follows the YYYYMMDDnn convention (2026-10-21).

DNSSEC

info

Signed, DS published at parent

Found

Validated by resolver: yes
Denial of existence: NSEC
Signatures valid until: 29 October 2026

DS at the parent

Key tag	Algorithm	Digest	Matches a key
21685	ECDSAP256SHA256 (13)	SHA256 DC22A57433BC2A35…	yes

DNSKEY in the zone

Key tag	Role	Algorithm
21685	KSK (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 21685 (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.
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

pass

37 records at the apex

Found

Read from: 141.80.181.237:53

Type	Value	TTL
SOA	ns1.mdc-berlin.eu. netz.mdc-berlin.de. 2026102108 10800 3600 604800 43200	43200
NS	ns3.mdc-berlin.eu.	172800
NS	ns2.mdc-berlin.eu.	172800
NS	ns1.mdc-berlin.eu.	172800
A	151.101.3.52	3600
A	151.101.131.52	3600
A	151.101.67.52	3600
A	151.101.195.52	3600
AAAA	2a04:4e42:400::820	3600
AAAA	2a04:4e42:600::820	3600
AAAA	2a04:4e42:a00::820	3600
AAAA	2a04:4e42::820	3600
AAAA	2a04:4e42:200::820	3600
AAAA	2a04:4e42:800::820	3600
AAAA	2a04:4e42:c00::820	3600
AAAA	2a04:4e42:e00::820	3600
MX	10 a2061.mx.srv.dfn.de.	3600
MX	10 c2061.mx.srv.dfn.de.	3600
MX	10 b2061.mx.srv.dfn.de.	3600
TXT	"anthropic-domain-verification-ybdh41=i6CdfwfrNjDjCUEr1T1bWltZR"	3600
TXT	"google-site-verification=c4ROUWr3RZiZvhNUkqAKv6k2UTwmyF1Uwg0aaNmBa5o"	3600
TXT	"google-site-verification=tL1cfON8VFrlAasH_MVldVVvPi2C_IfBkBYKrzUNvYM"	3600
TXT	"google-gws-recovery-domain-verification=56386351"	3600
TXT	"openai-domain-verification=dv-kEI2oyvOKbm9jPuq6d1p9x6G"	3600
TXT	"google-site-verification=fszb6_J6qOdA493Mc4XIt8-ByxHLwZAafoZw_PFmuAM"	3600
TXT	"v=spf1 ip4:35.180.69.77 ip4:35.190.213.245 ip4:141.80.113.48/28 include:_spf.o206.mx.srv.dfn.de include:spf.de.umantis.com include:spf.gisa.de -all"	3600
TXT	"have-i-been-pwned-verification=dweb_s8kihcagj0r8w5z929jys0gj"	3600
TXT	"facebook-domain-verification=k4vsjhz0c1ugd02l4woa4c5alop2ig"	3600
TXT	"google-gws-recovery-domain-verification=55664146"	3600
TXT	"HARICA-6MHb3CJXeXSE80sXzPn"	3600
CAA	0 issue "pki.dfn.de"	86400
CAA	0 issue "harica.gr"	86400
CAA	0 issue "letsencrypt.org"	86400
CAA	0 issue "certainly.com"	86400
CAA	0 issue "certum.pl"	86400
CAA	0 issue "amazon.com"	86400
CAA	0 issue "sectigo.com"	86400

Checks

✓ TTLs within range #32

TTLs: A 1h, AAAA 1h, MX 1h, NS 2d. The NS TTL at the parent is 1d 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: pki.dfn.de, harica.gr, letsencrypt.org, certainly.com, certum.pl, amazon.com, sectigo.com.