fh-zwickau.de

Checked 21 October 2026, 22:20 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

deneb.dfn.de, zeus.hrz.fh-zwickau.de, zeus2.hrz.fh-zwickau.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
deneb.dfn.de, zeus.hrz.fh-zwickau.de, zeus2.hrz.fh-zwickau.de
NS in the zone
deneb.dfn.de, zeus.hrz.fh-zwickau.de, zeus2.hrz.fh-zwickau.de
NameserverAddressesNetwork (AS)Glue
deneb.dfn.de192.76.176.9 2001:638:800:1::9AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
zeus.hrz.fh-zwickau.de141.32.192.17AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE141.32.192.17
zeus2.hrz.fh-zwickau.de141.32.192.22AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE141.32.192.22

Checks

  • ✓ 3 nameservers #6
    Delegated to deneb.dfn.de, zeus.hrz.fh-zwickau.de, zeus2.hrz.fh-zwickau.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: zeus.hrz.fh-zwickau.de, zeus2.hrz.fh-zwickau.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: zeus.hrz.fh-zwickau.de, zeus2.hrz.fh-zwickau.de.
    #13

Nameservers

info

4 of 4 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
deneb.dfn.de 192.76.176.9NOERROR, 14 ms, authoritativenoyes / yesrefused0
deneb.dfn.de 2001:638:800:1::9NOERROR, 14 ms, authoritativenoyes / yesrefused0
zeus.hrz.fh-zwickau.de 141.32.192.17NOERROR, 18 ms, authoritativenoyes / yesrefusedComputer sagt nein...
zeus2.hrz.fh-zwickau.de 141.32.192.22NOERROR, 18 ms, authoritativenoyes / yesrefusedComputer sagt nein...

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.
  • i
    Identifying string disclosed
    These nameservers answer version queries with a string that is not a version number: deneb.dfn.de: "0"; zeus.hrz.fh-zwickau.de: "Computer sagt nein..."; zeus2.hrz.fh-zwickau.de: "Computer sagt nein...".
    #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 2026102107 · primary zeus.hrz.fh-zwickau.de

Found

Primary (MNAME)
zeus.hrz.fh-zwickau.de
Contact (RNAME)
dnsmaster.fh-zwickau.de
Serial
2026102107
Refresh / retry
10800 s / 1800 s
Expire
1209600 s
Negative TTL
180 s

Serial per nameserver

NameserverSerial
deneb.dfn.de (192.76.176.9)2026102107
deneb.dfn.de (2001:638:800:1::9)2026102107
zeus.hrz.fh-zwickau.de (141.32.192.17)2026102107
zeus2.hrz.fh-zwickau.de (141.32.192.22)2026102107

Checks

  • ✓ Serial 2026102107 everywhere #22
    All nameservers serve the same version of the zone.
  • !
    Unusual SOA timers
    negative caching TTL (minimum) 3m is outside 5m–1d (RFC 2308 recommends 1–3 hours). Current values: refresh 3h, retry 30m, expire 14d, negative TTL 3m.
    #23
  • ✓ Primary is a public nameserver #24
    The primary nameserver zeus.hrz.fh-zwickau.de is one of the listed nameservers.
  • ✓ Contact dnsmaster@fh-zwickau.de #25
    The SOA RNAME dnsmaster.fh-zwickau.de means dnsmaster@fh-zwickau.de.
  • ✓ Date-based serial #26
    The serial 2026102107 follows the YYYYMMDDnn convention (2026-10-21).

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

pass

14 records at the apex

Found

Read from
192.76.176.9:53
TypeValueTTL
SOAzeus.hrz.fh-zwickau.de. dnsmaster.fh-zwickau.de. 2026102107 10800 1800 1209600 180900
NSdeneb.dfn.de.900
NSzeus.hrz.fh-zwickau.de.900
NSzeus2.hrz.fh-zwickau.de.900
A141.32.46.132900
MX10 a1211.mx.srv.dfn.de.900
MX10 b1211.mx.srv.dfn.de.900
MX10 c1211.mx.srv.dfn.de.900
TXT"v=spf1 ip4:141.32.72.0/24 include:_spf.o121.mx.srv.dfn.de ~all"900
TXT"google-site-verification=iQMzULEbCCI4RkjmyhfeSjJYHlUToP55JSrNGQPRCDA"900
TXT"HARICA-6I2QyTvPvcgASLt4sia"900
CAA0 issue "harica.gr"900
CAA0 issue "pki.dfn.de"900
CAA0 issue "sectigo.com"900

Checks

  • ✓ TTLs within range #32
    TTLs: A 15m, MX 15m, NS 15m. The NS TTL at the parent is 1d and in the zone 15m; 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: harica.gr, pki.dfn.de, sectigo.com.