thws.de

Checked 22 October 2026, 00:40 UTC · via 8.8.8.8
!Passed with warnings
21 passed 4 warnings 0 failed 7 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

warn

ns1.fhws.de, ns2.fhws.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
ns1.fhws.de, ns2.fhws.de
NS in the zone
dns-1.dfn.de, ns1.fhws.de, ns2.fhws.de
NameserverAddressesNetwork (AS)Glue
dns-1.dfn.de (zone only)193.174.75.50 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-
ns1.fhws.de194.94.48.183AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE194.94.48.183
ns2.fhws.de194.94.48.184AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE194.94.48.184

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: ns1.fhws.de, ns2.fhws.de.
    #6
  • !
    NS sets differ
    The nameservers at the parent and in the zone should be the same. Only in the zone: dns-1.dfn.de. dns-1.dfn.de, ns1.fhws.de, ns2.fhws.de report NS dns-1.dfn.de ns1.fhws.de ns2.fhws.de.
    #7
  • ✓ 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 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: ns1.fhws.de, ns2.fhws.de.
    #13

Nameservers

info

4 of 4 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, 13 ms, authoritativenoyes / yesrefused0
ns1.fhws.de 194.94.48.183NOERROR, 11 ms, authoritativenoyes / yesrefused-
ns2.fhws.de 194.94.48.184NOERROR, 11 ms, authoritativenoyes / yesrefused-

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: dns-1.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 1717 · primary ns1.fhws.de

Found

Primary (MNAME)
ns1.fhws.de
Contact (RNAME)
hostmaster.fhws.de
Serial
1717
Refresh / retry
86400 s / 7200 s
Expire
3600000 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
dns-1.dfn.de (193.174.75.50)1717
dns-1.dfn.de (2001:638:d:b101::1)1717
ns1.fhws.de (194.94.48.183)1717
ns2.fhws.de (194.94.48.184)1717

Checks

  • ✓ Serial 1717 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 1d, retry 2h, expire 1000h, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns1.fhws.de is one of the listed nameservers.
  • ✓ Contact hostmaster@fhws.de #25
    The SOA RNAME hostmaster.fhws.de means hostmaster@fhws.de.
  • ✓ Counter serial #26
    The serial 1717 is a plain counter.

DNSSEC

warn

Signed, but no DS at parent

Found

Validated by resolver
no
Denial of existence
NSEC3
NSEC3
50 iterations, 16-byte salt
Signatures valid until
27 October 2026

DNSKEY in the zone

Key tagRoleAlgorithm
24309ZSK (256)RSASHA256 (8)
41030KSK (257)RSASHA256 (8)
46067KSK (257)RSASHA256 (8)
12573ZSK (256)RSASHA256 (8)

Checks

  • !
    Signed but not delegated securely
    The zone is signed but the parent has no DS record, so the signatures are not used. Publish the DS record at your registrar.
    #27
  • ✓ Modern algorithms #29
    Key algorithms: RSASHA256 (8).
  • !
    Signatures expire soon
    The earliest signature expires at 2026-10-27 00:53 UTC (in 120h0m0s). Check that automatic re-signing works.
    #30
  • !
    NSEC3 with extra iterations or salt
    NSEC3 uses 50 iterations and a 16-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

pass

25 records at the apex

Found

Read from
193.174.75.50:53
TypeValueTTL
SOAns1.fhws.de. hostmaster.fhws.de. 1717 86400 7200 3600000 3600172800
NSdns-1.dfn.de.3600
NSns2.fhws.de.3600
NSns1.fhws.de.3600
A193.175.30.13600
MX10 b2801.mx.srv.dfn.de.3600
MX10 a2801.mx.srv.dfn.de.3600
MX10 c2801.mx.srv.dfn.de.3600
TXT"autodesk-domain-verification=DL7NBm4dtoRM1U5n43Tg"3600
TXT"Cx2pKk3B1GBke3daQxmqSHRmUPq3TWZ2t00X6LLgt8KXQRizpsAFcAJBeNEHDiTFL8JHQ4fswO7oyfh5Of0vbA=="3600
TXT"v=spf1 mx a:bvbvxmail.bib-bvb.de include:spf.sendinblue.com include:_spf.o280.mx.srv.dfn.de include:_spf.kdv.bayern include:spf.protection.outlook.com ~all"3600
TXT"adobe-idp-site-verification=4997676fc33c004f90c04984b5ea7cffda9762b87eeb551ece388b36519ebca4"3600
TXT"MS=ms91459028"3600
TXT"HARICA-wcHJpJBUYIETYTY2Jpq"3600
TXT"brevo-code:187e482e08746663c548c581d5cd1636"3600
TXT"ZOOM_verify_BnK3TE657SKq8kNksaqJlh"3600
TXT"sendinblue-code:03ea135ec69c04b25207cb2b2e3a3626"3600
TXT"apple-domain-verification=xU4uiwAgPC40LHUe"3600
TXT"google-site-verification=ma3vdq_qAh6emBWU9IjkVc-TNd9NIFpEK_alncqW-f4"3600
TXT"brevo-code:e9667d3b3dfe95df4b6d7807ee94cd2b"3600
CAA0 issue "harica.gr"3600
CAA0 issue "pki.dfn.de"3600
CAA0 issue "sectigo.com"3600
CAA0 issue "digicert.com"3600
CAA0 iodef "mailto:patrick.schuetz@fhws.de"3600

Checks

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