htwk-leipzig.de

Checked 21 October 2026, 22:51 UTC · via 8.8.8.8
!Passed with warnings
21 passed 2 warnings 0 failed 6 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-3.dfn.de, dns01.htwk-leipzig.de, dns02.htwk-leipzig.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-3.dfn.de, dns01.htwk-leipzig.de, dns02.htwk-leipzig.de
NS in the zone
dns-3.dfn.de, dns01.htwk-leipzig.de, dns02.htwk-leipzig.de
NameserverAddressesNetwork (AS)Glue
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-
dns01.htwk-leipzig.de141.57.1.219AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE141.57.1.219
dns02.htwk-leipzig.de141.57.1.220AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE141.57.1.220

Checks

  • ✓ 3 nameservers #6
    Delegated to dns-3.dfn.de, dns01.htwk-leipzig.de, dns02.htwk-leipzig.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: dns01.htwk-leipzig.de, dns02.htwk-leipzig.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 2 IPv4 /24s and 1 IPv6 /48.
  • 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): 4 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
  • i
    Partly IPv6
    These nameservers have no IPv6 address: dns01.htwk-leipzig.de, dns02.htwk-leipzig.de.
    #13

Nameservers

warn

4 of 4 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
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
dns01.htwk-leipzig.de 141.57.1.219NOERROR, 12 ms, authoritativenoyes / yesrefused-
dns02.htwk-leipzig.de 141.57.1.220NOERROR, 16 ms, authoritativenoyes / yesrefused9.20.29

Checks

  • ✓ All respond #14
    All 4 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: dns02.htwk-leipzig.de: "9.20.29". 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 2017013221 · primary dns01.htwk-leipzig.de

Found

Primary (MNAME)
dns01.htwk-leipzig.de
Contact (RNAME)
nsmaster.htwk-leipzig.de
Serial
2017013221
Refresh / retry
10800 s / 3600 s
Expire
2419200 s
Negative TTL
900 s

Serial per nameserver

NameserverSerial
dns-3.dfn.de (193.174.75.58)2017013221
dns-3.dfn.de (2001:638:d:b103::1)2017013221
dns01.htwk-leipzig.de (141.57.1.219)2017013221
dns02.htwk-leipzig.de (141.57.1.220)2017013221

Checks

  • ✓ Serial 2017013221 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 3h, retry 1h, expire 28d, negative TTL 15m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver dns01.htwk-leipzig.de is one of the listed nameservers.
  • ✓ Contact nsmaster@htwk-leipzig.de #25
    The SOA RNAME nsmaster.htwk-leipzig.de means nsmaster@htwk-leipzig.de.
  • ✓ Timestamp serial #26
    The serial 2017013221 is a Unix timestamp (2033-12-01 01:27 UTC).

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

info

17 records at the apex

Found

Read from
193.174.75.58:53
TypeValueTTL
SOAdns01.htwk-leipzig.de. nsmaster.htwk-leipzig.de. 2017013221 10800 3600 2419200 900300
NSdns-3.dfn.de.300
NSdns01.htwk-leipzig.de.300
NSdns02.htwk-leipzig.de.300
A141.57.5.215300
MX10 c1271.mx.srv.dfn.de.300
MX10 b1271.mx.srv.dfn.de.300
MX10 a1271.mx.srv.dfn.de.300
TXT"v=spf1 ip4:141.57.19.52 ip4:141.57.19.53 ip4:141.57.19.54 ip4:141.57.19.55 ip4:141.57.19.60 include:spf-eu.exlibrisgroup.com a:mail.sop-at.com include:_spf.b-ite.com ~all"300
TXT"HARICA-OdZu0go6FtQqYTafxs4"300
TXT"apple-domain-verification=spao9sGZ75AY3RxD"300
TXT"google-site-verification=DmTqQs2RBrfC1Q5wF-5FOgmU35_LVT4xQX1k9QOJr-o"300
TXT"_telesec-domain-validation=341831_2025-10-09_JIOYnUpARsNrqpzBS6oso9H2v5SdZaRqEGevsmx9tVouprQZT2"300
TXT"ZOOM_verify_cpUvqJqcRCqRE8M0oFlWTw"300
TXT"MS=ms48871753"300
TXT"MS=D9BDD0F6F52574A6D96972AC8A083552F0544BE0"300
TXT"adobe-idp-site-verification=f3050ba8c13218d7044a749e77c29f6d92130d174bb15f2bdb9376268a0ee758"300

Checks

  • ✓ TTLs within range #32
    TTLs: A 5m, MX 5m, NS 5m. The NS TTL at the parent is 1d and in the zone 5m; 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.
  • i
    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