uni-saarland.de

Checked 22 October 2026, 00:50 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

warn

dns-1.dfn.de, ns.cs.uni-sb.de, ns.rz.uni-saarland.de, ns.uni-sb.de, ns1.rz.uni-saarland.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-1.dfn.de, ns.cs.uni-sb.de, ns.rz.uni-saarland.de, ns.uni-sb.de, ns1.rz.uni-saarland.de
NS in the zone
dns-1.dfn.de, ns.cs.uni-sb.de, ns.rz.uni-saarland.de, ns1.rz.uni-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.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.uni-sb.de (parent only)134.96.254.1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.96.254.1
ns1.rz.uni-saarland.de134.96.100.105 2001:638:200:811b:0:1:0:1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.96.100.105 2001:638:200:811b:0:1:0:1

Checks

  • ✓ 5 nameservers #6
    Delegated to dns-1.dfn.de, ns.cs.uni-sb.de, ns.rz.uni-saarland.de, ns.uni-sb.de, ns1.rz.uni-saarland.de.
  • !
    NS sets differ
    The nameservers at the parent and in the zone should be the same. Only at the parent: ns.uni-sb.de. dns-1.dfn.de, ns.cs.uni-sb.de, ns.rz.uni-saarland.de, ns.uni-sb.de, ns1.rz.uni-saarland.de report NS dns-1.dfn.de ns.cs.uni-sb.de ns.rz.uni-saarland.de ns1.rz.uni-saarland.de.
    #7
  • ✓ Glue present and correct #8
    Glue is published for the nameservers inside the zone: ns.rz.uni-saarland.de, ns1.rz.uni-saarland.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 2 IPv6 /48s.
  • 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): 7 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.cs.uni-sb.de, ns.rz.uni-saarland.de, ns.uni-sb.de.
    #13

Nameservers

info

7 of 7 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, 14 ms, authoritativenoyes / yesrefused0
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.uni-sb.de 134.96.254.1NOERROR, 8 ms, authoritativenoyes / yesrefused-
ns1.rz.uni-saarland.de 134.96.100.105NOERROR, 12 ms, authoritativenoyes / yesrefusedunknown
ns1.rz.uni-saarland.de 2001:638:200:811b:0:1:0:1NOERROR, 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.
  • i
    Identifying string disclosed
    These nameservers answer version queries with a string that is not a version number: dns-1.dfn.de: "0"; ns.rz.uni-saarland.de: "0"; ns1.rz.uni-saarland.de: "unknown".
    #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 2026102100 · primary ns.rz.uni-saarland.de

Found

Primary (MNAME)
ns.rz.uni-saarland.de
Contact (RNAME)
hostmaster.uni-saarland.de
Serial
2026102100
Refresh / retry
3600 s / 1800 s
Expire
1209600 s
Negative TTL
1800 s

Serial per nameserver

NameserverSerial
dns-1.dfn.de (193.174.75.50)2026102100
dns-1.dfn.de (2001:638:d:b101::1)2026102100
ns.cs.uni-sb.de (134.96.252.20)2026102100
ns.rz.uni-saarland.de (134.96.7.7)2026102100
ns.uni-sb.de (134.96.254.1)2026102100
ns1.rz.uni-saarland.de (134.96.100.105)2026102100
ns1.rz.uni-saarland.de (2001:638:200:811b:0:1:0:1)2026102100

Checks

  • ✓ Serial 2026102100 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 1h, retry 30m, expire 14d, negative TTL 30m.
  • ✓ 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 2026102100 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

16 records at the apex

Found

Read from
193.174.75.50:53
TypeValueTTL
SOAns.rz.uni-saarland.de. hostmaster.uni-saarland.de. 2026102100 3600 1800 1209600 180086400
NSns.rz.uni-saarland.de.86400
NSdns-1.dfn.de.86400
NSns.cs.uni-sb.de.86400
NSns1.rz.uni-saarland.de.86400
A134.96.7.127600
MX20 m-relay2.rz.uni-saarland.de.86400
MX50 m-relay.rz.uni-saarland.de.86400
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 include:spf.protection.outlook.com ~all"3600
TXT"google-site-verification=_bIgsm1mPJXZKodZ8LPMfd7zuZkibUHVtVwOJVgPXNI"3600
TXT"anthropic-domain-verification-n24e8j=F7nPGmwlGURUWy1ur5HjZbSb3"3600
CAA0 issue "sectigo.com"86400
CAA0 issue "pki.dfn.de"86400
CAA0 issue "digicert.com"86400
CAA0 issue "harica.gr"86400
CAA0 issue "letsencrypt.org"86400

Checks

  • ✓ TTLs within range #32
    TTLs: A 10m, MX 1d, NS 1d.
  • ✓ 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: sectigo.com, pki.dfn.de, digicert.com, harica.gr, letsencrypt.org.