uni-ulm.de

Checked 22 October 2026, 00:50 UTC · via 8.8.8.8
!Passed with warnings
23 passed 2 warnings 0 failed 4 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, dns1.belwue.de, dns1.uni-ulm.de, dns3.belwue.de, dns5.belwue.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-1.dfn.de, dns1.belwue.de, dns1.uni-ulm.de, dns3.belwue.de, dns5.belwue.de
NS in the zone
dns-1.dfn.de, dns1.belwue.de, dns1.uni-ulm.de, dns3.belwue.de, dns5.belwue.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-
dns1.belwue.de129.143.2.10 2001:7c0::53:10AS553 BELWUE - Universitaet Stuttgart, DE AS553 BELWUE - Universitaet Stuttgart, DE129.143.2.10 2001:7c0::53:10
dns1.uni-ulm.de134.60.1.112 2001:7c0:3100::112AS553 BELWUE - Universitaet Stuttgart, DE AS553 BELWUE - Universitaet Stuttgart, DE134.60.1.112 2001:7c0:3100::112
dns3.belwue.de129.143.253.133 2001:7c0:0:253::133AS553 BELWUE - Universitaet Stuttgart, DE AS553 BELWUE - Universitaet Stuttgart, DE129.143.253.133 2001:7c0:0:253::133
dns5.belwue.de129.143.4.5 2001:7c0::53:5AS553 BELWUE - Universitaet Stuttgart, DE AS553 BELWUE - Universitaet Stuttgart, DE129.143.4.5 2001:7c0::53:5

Checks

  • ✓ 5 nameservers #6
    Delegated to dns-1.dfn.de, dns1.belwue.de, dns1.uni-ulm.de, dns3.belwue.de, dns5.belwue.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.uni-ulm.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 5 IPv4 /24s and 3 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS553 (BELWUE - Universitaet Stuttgart, DE): 8 addresses; AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE): 2 addresses.
  • 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

warn

10 of 10 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns-1.dfn.de 193.174.75.50NOERROR, 12 ms, authoritativenoyes / yesrefused0
dns-1.dfn.de 2001:638:d:b101::1NOERROR, 14 ms, authoritativenoyes / yesrefused0
dns1.belwue.de 129.143.2.10NOERROR, 7 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)
dns1.belwue.de 2001:7c0::53:10NOERROR, 7 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)
dns1.uni-ulm.de 134.60.1.112NOERROR, 8 ms, authoritativenoyes / yesrefusednot disclosed
dns1.uni-ulm.de 2001:7c0:3100::112NOERROR, 9 ms, authoritativenoyes / yesrefusednot disclosed
dns3.belwue.de 129.143.253.133NOERROR, 7 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)
dns3.belwue.de 2001:7c0:0:253::133NOERROR, 7 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)
dns5.belwue.de 129.143.4.5NOERROR, 7 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)
dns5.belwue.de 2001:7c0::53:5NOERROR, 7 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)

Checks

  • ✓ All respond #14
    All 10 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: dns1.belwue.de: "PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)"; dns3.belwue.de: "PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)"; dns5.belwue.de: "PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)". 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 2026102128 · primary dns1.uni-ulm.de

Found

Primary (MNAME)
dns1.uni-ulm.de
Contact (RNAME)
hostmaster.uni-ulm.de
Serial
2026102128
Refresh / retry
21600 s / 3600 s
Expire
1209600 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
dns-1.dfn.de (193.174.75.50)2026102128
dns-1.dfn.de (2001:638:d:b101::1)2026102128
dns1.belwue.de (129.143.2.10)2026102128
dns1.belwue.de (2001:7c0::53:10)2026102128
dns1.uni-ulm.de (134.60.1.112)2026102128
dns1.uni-ulm.de (2001:7c0:3100::112)2026102128
dns3.belwue.de (129.143.253.133)2026102128
dns3.belwue.de (2001:7c0:0:253::133)2026102128
dns5.belwue.de (129.143.4.5)2026102128
dns5.belwue.de (2001:7c0::53:5)2026102128

Checks

  • ✓ Serial 2026102128 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 6h, retry 1h, expire 14d, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver dns1.uni-ulm.de is one of the listed nameservers.
  • ✓ Contact hostmaster@uni-ulm.de #25
    The SOA RNAME hostmaster.uni-ulm.de means hostmaster@uni-ulm.de.
  • ✓ Date-based serial #26
    The serial 2026102128 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

info

15 records at the apex

Found

Read from
193.174.75.50:53
TypeValueTTL
SOAdns1.uni-ulm.de. hostmaster.uni-ulm.de. 2026102128 21600 3600 1209600 3600172800
NSdns5.belwue.de.3600
NSdns1.belwue.de.3600
NSdns-1.dfn.de.3600
NSdns1.uni-ulm.de.3600
NSdns3.belwue.de.3600
A134.60.1.202172800
A134.60.1.177172800
AAAA2001:7c0:3100::177172800
AAAA2001:7c0:3100::202172800
MX10 b2951.mx.srv.dfn.de.172800
MX10 a2951.mx.srv.dfn.de.172800
MX10 c2951.mx.srv.dfn.de.172800
TXT"anthropic-domain-verification-whgdh1=HvViRkziWPnbIjSxjpoLVSjLk"172800
TXT"v=spf1 redirect=_spf.uni-ulm.de"172800

Checks

  • ✓ TTLs within range #32
    TTLs: A 2d, AAAA 2d, MX 2d, 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.
  • 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