uni-sb.de

Checked 22 October 2026, 00:50 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

dns1.belwue.de, ns.cs.uni-sb.de, ns.rz.uni-saarland.de, ns.rz.uni-sb.de, ns.uni-sb.de, ns1.rz.uni-sb.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns1.belwue.de, ns.cs.uni-sb.de, ns.rz.uni-saarland.de, ns.rz.uni-sb.de, ns.uni-sb.de, ns1.rz.uni-sb.de
NS in the zone
dns1.belwue.de, ns.cs.uni-sb.de, ns.rz.uni-saarland.de, ns.rz.uni-sb.de, ns.uni-sb.de, ns1.rz.uni-sb.de
NameserverAddressesNetwork (AS)Glue
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
ns.cs.uni-sb.de134.96.252.20AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.96.252.20
ns.rz.uni-saarland.de134.96.7.7AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.96.7.7
ns.rz.uni-sb.de134.96.7.7AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.96.7.7
ns.uni-sb.de134.96.254.1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.96.254.1
ns1.rz.uni-sb.de134.96.100.105AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.96.100.105

Checks

  • ✓ 6 nameservers #6
    Delegated to dns1.belwue.de, ns.cs.uni-sb.de, ns.rz.uni-saarland.de, ns.rz.uni-sb.de, ns.uni-sb.de, ns1.rz.uni-sb.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: ns.cs.uni-sb.de, ns.rz.uni-sb.de, ns.uni-sb.de, ns1.rz.uni-sb.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 1 IPv6 /48.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS553 (BELWUE - Universitaet Stuttgart, DE): 2 addresses; AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE): 5 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
  • i
    Partly IPv6
    These nameservers have no IPv6 address: ns.cs.uni-sb.de, ns.rz.uni-saarland.de, ns.rz.uni-sb.de, ns.uni-sb.de, ns1.rz.uni-sb.de.
    #13

Nameservers

warn

7 of 7 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
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)
ns.cs.uni-sb.de 134.96.252.20NOERROR, 12 ms, authoritativenoyes / yesrefused-
ns.rz.uni-saarland.de 134.96.7.7NOERROR, 8 ms, authoritativenoyes / yesrefused0
ns.rz.uni-sb.de 134.96.7.7NOERROR, 8 ms, authoritativenoyes / yesrefused0
ns.uni-sb.de 134.96.254.1NOERROR, 8 ms, authoritativenoyes / yesrefused-
ns1.rz.uni-sb.de 134.96.100.105NOERROR, 12 ms, authoritativenoyes / yesrefusedunknown

Checks

  • ✓ All respond #14
    All 7 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)". 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 2026032500 · primary ns.uni-sb.de

Found

Primary (MNAME)
ns.uni-sb.de
Contact (RNAME)
net.cs.uni-sb.de
Serial
2026032500
Refresh / retry
21600 s / 3600 s
Expire
900000 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
dns1.belwue.de (129.143.2.10)2026032500
dns1.belwue.de (2001:7c0::53:10)2026032500
ns.cs.uni-sb.de (134.96.252.20)2026032500
ns.rz.uni-saarland.de (134.96.7.7)2026032500
ns.rz.uni-sb.de (134.96.7.7)2026032500
ns.uni-sb.de (134.96.254.1)2026032500
ns1.rz.uni-sb.de (134.96.100.105)2026032500

Checks

  • ✓ Serial 2026032500 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 6h, retry 1h, expire 250h, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns.uni-sb.de is one of the listed nameservers.
  • ✓ Contact net@cs.uni-sb.de #25
    The SOA RNAME net.cs.uni-sb.de means net@cs.uni-sb.de.
  • ✓ Date-based serial #26
    The serial 2026032500 follows the YYYYMMDDnn convention (2026-03-25).

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

12 records at the apex

Found

Read from
129.143.2.10:53
TypeValueTTL
SOAns.uni-sb.de. net.cs.uni-sb.de. 2026032500 21600 3600 900000 864003600
NSns.cs.uni-sb.de.3600
NSns.rz.uni-sb.de.3600
NSns.uni-sb.de.3600
NSns.rz.uni-saarland.de.3600
NSdns1.belwue.de.3600
NSns1.rz.uni-sb.de.3600
A134.96.7.1283600
MX50 mail.uni-sb.de.3600
MX53 mailin.cs.uni-sb.de.3600
MX55 mail.cs.uni-sb.de.3600
TXT"v=spf1 mx ip4:134.96.254.200 ip4:134.96.254.201 ip4:134.96.252.33 ip4:134.96.7.0/24 ip4:134.96.40.64/28 ip6:2001:638:200:853F:0:1::/112 ~all"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.
  • 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