uol.de

Checked 22 October 2026, 00:50 UTC · via 8.8.8.8
!Passed with warnings
21 passed 1 warning 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

info

dns-2.dfn.de, ns01.uni-oldenburg.de, ns02.uni-oldenburg.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-2.dfn.de, ns01.uni-oldenburg.de, ns02.uni-oldenburg.de
NS in the zone
dns-2.dfn.de, ns01.uni-oldenburg.de, ns02.uni-oldenburg.de
NameserverAddressesNetwork (AS)Glue
dns-2.dfn.de193.174.75.54 2001:638:d:b102::1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
ns01.uni-oldenburg.de134.106.40.10AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.106.40.10
ns02.uni-oldenburg.de134.106.49.4AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.106.49.4

Checks

  • ✓ 3 nameservers #6
    Delegated to dns-2.dfn.de, ns01.uni-oldenburg.de, ns02.uni-oldenburg.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 3 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: ns01.uni-oldenburg.de, ns02.uni-oldenburg.de.
    #13

Nameservers

info

4 of 4 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns-2.dfn.de 193.174.75.54NOERROR, 7 ms, authoritativenoyes / yesrefused0
dns-2.dfn.de 2001:638:d:b102::1NOERROR, 7 ms, authoritativenoyes / yesrefused0
ns01.uni-oldenburg.de 134.106.40.10NOERROR, 21 ms, authoritativenoyes / yesrefused-
ns02.uni-oldenburg.de 134.106.49.4NOERROR, 22 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-2.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 776505123 · primary ns01.uni-oldenburg.de

Found

Primary (MNAME)
ns01.uni-oldenburg.de
Contact (RNAME)
ipserv.uni-oldenburg.de
Serial
776505123
Refresh / retry
3600 s / 900 s
Expire
1209600 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
dns-2.dfn.de (193.174.75.54)776505123
dns-2.dfn.de (2001:638:d:b102::1)776505123
ns01.uni-oldenburg.de (134.106.40.10)776505123
ns02.uni-oldenburg.de (134.106.49.4)776505123

Checks

  • ✓ Serial 776505123 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 1h, retry 15m, expire 14d, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns01.uni-oldenburg.de is one of the listed nameservers.
  • ✓ Contact ipserv@uni-oldenburg.de #25
    The SOA RNAME ipserv.uni-oldenburg.de means ipserv@uni-oldenburg.de.
  • ✓ Counter serial #26
    The serial 776505123 is a plain counter.

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

9 records at the apex

Found

Read from
193.174.75.54:53
TypeValueTTL
SOAns01.uni-oldenburg.de. ipserv.uni-oldenburg.de. 776505123 3600 900 1209600 36003600
NSdns-2.dfn.de.86400
NSns02.uni-oldenburg.de.86400
NSns01.uni-oldenburg.de.86400
A134.106.87.1043600
AAAA2001:638:705:3f15::1043600
MX100 smtpmx.uni-oldenburg.de.3600
TXT"HARICA-u19SQnul4sZucWiQfLV"3600
TXT"v=spf1 mx ip4:134.106.141.0/24 ~all"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 1h, AAAA 1h, MX 1h, 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.
  • 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