th-nuernberg.de

Checked 22 October 2026, 00:40 UTC · via 8.8.8.8
!Passed with warnings
26 passed 2 warnings 0 failed 5 info

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

dns-1.dfn.de, dns-3.dfn.de, dns1.th-nuernberg.de, dns2.th-nuernberg.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-1.dfn.de, dns-3.dfn.de, dns1.th-nuernberg.de, dns2.th-nuernberg.de
NS in the zone
dns-1.dfn.de, dns-3.dfn.de, dns1.th-nuernberg.de, dns2.th-nuernberg.de
NameserverAddressesNetwork (AS)Glue
dns-1.dfn.de193.174.75.50 2001:638:d:b101::1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
dns-3.dfn.de193.174.75.58 2001:638:d:b103::1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
dns1.th-nuernberg.de141.75.25.80 2001:638:a04:d025::80AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE141.75.25.80 2001:638:a04:d025::80
dns2.th-nuernberg.de141.75.8.20 2001:638:a04:d008::20AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE141.75.8.20 2001:638:a04:d008::20

Checks

  • ✓ 4 nameservers #6
    Delegated to dns-1.dfn.de, dns-3.dfn.de, dns1.th-nuernberg.de, dns2.th-nuernberg.de.
  • ✓ Parent and zone agree #7
    The parent delegation and the zone's NS records list the same nameservers.
  • ✓ Glue present and correct #8
    Glue is published for the nameservers inside the zone: dns1.th-nuernberg.de, dns2.th-nuernberg.de.
  • ✓ 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.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE): 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
  • i
    All nameserver names under .de
    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

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns-1.dfn.de 193.174.75.50NOERROR, 14 ms, authoritativenoyes / yesrefused0
dns-1.dfn.de 2001:638:d:b101::1NOERROR, 12 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 193.174.75.58NOERROR, 8 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 2001:638:d:b103::1NOERROR, 10 ms, authoritativenoyes / yesrefused0
dns1.th-nuernberg.de 141.75.25.80NOERROR, 10 ms, authoritativenoyes / yesrefused-
dns1.th-nuernberg.de 2001:638:a04:d025::80NOERROR, 10 ms, authoritativenoyes / yesrefused-
dns2.th-nuernberg.de 141.75.8.20NOERROR, 10 ms, authoritativenoyes / yesrefused-
dns2.th-nuernberg.de 2001:638:a04:d008::20NOERROR, 13 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.
  • i
    Identifying string disclosed
    These nameservers answer version queries with a string that is not a version number: dns-1.dfn.de: "0"; dns-3.dfn.de: "0".
    #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 2026100203 · primary dns1.th-nuernberg.de

Found

Primary (MNAME)
dns1.th-nuernberg.de
Contact (RNAME)
hostmaster.th-nuernberg.de
Serial
2026100203
Refresh / retry
28800 s / 7200 s
Expire
1209600 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
dns-1.dfn.de (193.174.75.50)2026100203
dns-1.dfn.de (2001:638:d:b101::1)2026100203
dns-3.dfn.de (193.174.75.58)2026100203
dns-3.dfn.de (2001:638:d:b103::1)2026100203
dns1.th-nuernberg.de (141.75.25.80)2026100203
dns1.th-nuernberg.de (2001:638:a04:d025::80)2026100203
dns2.th-nuernberg.de (141.75.8.20)2026100203
dns2.th-nuernberg.de (2001:638:a04:d008::20)2026100203

Checks

  • ✓ Serial 2026100203 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 8h, retry 2h, expire 14d, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver dns1.th-nuernberg.de is one of the listed nameservers.
  • ✓ Contact hostmaster@th-nuernberg.de #25
    The SOA RNAME hostmaster.th-nuernberg.de means hostmaster@th-nuernberg.de.
  • ✓ Date-based serial #26
    The serial 2026100203 follows the YYYYMMDDnn convention (2026-10-02).

DNSSEC

warn

Signed, DS published at parent

Found

Validated by resolver
yes
Denial of existence
NSEC3
NSEC3
0 iterations, 8-byte salt
Signatures valid until
20 November 2026

DS at the parent

Key tagAlgorithmDigestMatches a key
40297RSASHA256 (8)SHA256 5C5C387BC88D8F51…yes

DNSKEY in the zone

Key tagRoleAlgorithm
40297KSK (257)RSASHA256 (8)
45246ZSK (256)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 40297 (SHA256).
  • ✓ Modern algorithms #29
    Key algorithms: RSASHA256 (8).
  • ✓ Signatures valid until 2026-11-20 #30
    The earliest DNSKEY/SOA signature expires at 2026-11-20 20:00 UTC.
  • !
    NSEC3 with extra iterations or salt
    NSEC3 uses 0 iterations and a 8-byte salt. RFC 9276 recommends 0 iterations and no salt: extra iterations cost resolvers CPU and add no real protection, and some validators treat high counts as insecure.
    #31

Records

warn

15 records at the apex

Found

Read from
193.174.75.50:53
TypeValueTTL
SOAdns1.th-nuernberg.de. hostmaster.th-nuernberg.de. 2026100203 28800 7200 1209600 8640086400
NSdns-1.dfn.de.86400
NSdns1.th-nuernberg.de.86400
NSdns2.th-nuernberg.de.86400
NSdns-3.dfn.de.86400
A141.75.201.123600
MX0 thnuernberg-de0e.mail.protection.outlook.com.3600
TXT"HARICA-jY1AGL1Lt499WVLxuxn"3600
TXT"adobe-idp-site-verification=ee6eefca2deba3a4b72e56a734cec3b45350a9ac3899a8095ff642442966bd91"3600
TXT"v=spf1 mx a:mailgw2.th-nuernberg.de a:bvbvxmail.bib-bvb.de a:mailer02.zib.de include:_spf.kdv-fh-bayern.de include:_spf.mail.lrz.de include:spf.protection.outlook.com -all"3600
TXT"MS=ms11561762"3600
CAA0 issue "harica.gr"3600
CAA0 iodev "mailto:security@th-nuernberg.de"3600
CAA0 issue "pki.dfn.de"3600
CAA0 issue "letsencrypt.org"3600

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.
  • !
    Unknown CAA tags
    These CAA tags are not defined: iodev. CAs must refuse to issue when an unknown tag is marked critical.
    #35