htwsaar.de

Checked 21 October 2026, 22:51 UTC · via 8.8.8.8
!Passed with warnings
22 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, ns.htw-saarland.de, ns.rz.uni-saarland.de, ns1.htw-saarland.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-1.dfn.de, ns.htw-saarland.de, ns.rz.uni-saarland.de, ns1.htw-saarland.de
NS in the zone
dns-1.dfn.de, ns.htw-saarland.de, ns.rz.uni-saarland.de, ns1.htw-saarland.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-
ns.htw-saarland.de134.96.208.98AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.96.208.98
ns.rz.uni-saarland.de134.96.7.7AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.96.7.7
ns1.htw-saarland.de134.96.216.214AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.96.216.214

Checks

  • ✓ 4 nameservers #6
    Delegated to dns-1.dfn.de, ns.htw-saarland.de, ns.rz.uni-saarland.de, ns1.htw-saarland.de.
  • ✓ 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 4 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): 5 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: ns.htw-saarland.de, ns.rz.uni-saarland.de, ns1.htw-saarland.de.
    #13

Nameservers

warn

5 of 5 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
ns.htw-saarland.de 134.96.208.98NOERROR, 12 ms, authoritativenoyes / yesrefusedHTWdS 0.8.3
ns.rz.uni-saarland.de 134.96.7.7NOERROR, 12 ms, authoritativenoyes / yesrefused0
ns1.htw-saarland.de 134.96.216.214NOERROR, 9 ms, authoritativenoyes / yesrefused9.11.36-RedHat-9.11.36-16.el8_10.8

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: ns.htw-saarland.de: "HTWdS 0.8.3"; ns1.htw-saarland.de: "9.11.36-RedHat-9.11.36-16.el8_10.8". 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 2026102101 · primary ns.rz.uni-saarland.de

Found

Primary (MNAME)
ns.rz.uni-saarland.de
Contact (RNAME)
hostmaster.uni-saarland.de
Serial
2026102101
Refresh / retry
14400 s / 3600 s
Expire
1209600 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
dns-1.dfn.de (193.174.75.50)2026102101
dns-1.dfn.de (2001:638:d:b101::1)2026102101
ns.htw-saarland.de (134.96.208.98)2026102101
ns.rz.uni-saarland.de (134.96.7.7)2026102101
ns1.htw-saarland.de (134.96.216.214)2026102101

Checks

  • ✓ Serial 2026102101 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 4h, retry 1h, expire 14d, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns.rz.uni-saarland.de is one of the listed nameservers.
  • ✓ Contact hostmaster@uni-saarland.de #25
    The SOA RNAME hostmaster.uni-saarland.de means hostmaster@uni-saarland.de.
  • ✓ Date-based serial #26
    The serial 2026102101 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

22 records at the apex

Found

Read from
193.174.75.50:53
TypeValueTTL
SOAns.rz.uni-saarland.de. hostmaster.uni-saarland.de. 2026102101 14400 3600 1209600 360043200
NSns.htw-saarland.de.43200
NSns.rz.uni-saarland.de.43200
NSdns-1.dfn.de.43200
NSns1.htw-saarland.de.43200
A134.96.210.1563600
MX40 mx-gate2.mail.hiz-saarland.de.43200
MX50 m-relay.rz.uni-saarland.de.43200
MX50 m-relay2.rz.uni-saarland.de.43200
MX30 mx-gate1.mail.hiz-saarland.de.43200
TXT"adobe-idp-site-verification=b8030a1ed47b4b48e005981cbd27f9a894ab1232caec537d13e0434006288ab2"3600
TXT"HARICA-nWWDL72lQxXW39En1fc"3600
TXT"v=spf1 a mx ip4:134.96.7.0/24 ip4:134.96.40.64/28 ip6:2001:638:200:853F:0:1::/112 ~all"3600
TXT"F37-KG8-n02"3600
TXT"autodesk-domain-verification=8IcSR0CBTytxaS1rCDOt"3600
TXT"MS=ms30387737"3600
TXT"apple-domain-verification=OmBfJDtXqXy5tKOT"3600
TXT"MS=B15777860A2752F9179590E0629A6D35DB7F8564"3600
TXT"qzCxpSarCHRbgnjLv9xUzB5aRPu1S53AaMCxGfIosovB7ip9eGzF6lXGMrhWcrYbv0fryMcyhg1shMGmXwtQbw=="3600
CAA0 issue "harica.gr"43200
CAA0 issue "letsencrypt.org"43200
CAA0 issue "pki.dfn.de"43200

Checks

  • ✓ TTLs within range #32
    TTLs: A 1h, MX 12h, NS 12h. The NS TTL at the parent is 1d and in the zone 12h; 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, letsencrypt.org, pki.dfn.de.