cochrane.de

Checked 21 October 2026, 22:10 UTC · via 8.8.8.8
!Passed with warnings
19 passed 2 warnings 0 failed 8 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, dns3.belwue.de, dns5.belwue.de, skl1.ukl.uni-freiburg.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns1.belwue.de, dns3.belwue.de, dns5.belwue.de, skl1.ukl.uni-freiburg.de
NS in the zone
dns1.belwue.de, dns3.belwue.de, dns5.belwue.de, skl1.ukl.uni-freiburg.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
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
skl1.ukl.uni-freiburg.de193.196.199.1AS553 BELWUE - Universitaet Stuttgart, DE-

Checks

  • ✓ 4 nameservers #6
    Delegated to dns1.belwue.de, dns3.belwue.de, dns5.belwue.de, skl1.ukl.uni-freiburg.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.
  • i
    One address family in one network
    all IPv6 addresses are in 2001:7c0::/48, while the other address family is spread over several networks.
    #10
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS553 (BELWUE - Universitaet Stuttgart, 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: skl1.ukl.uni-freiburg.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)
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, 10 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)
skl1.ukl.uni-freiburg.de 193.196.199.1NOERROR, 22 ms, authoritativenoyes / yesrefused-

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)"; 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 689873552 · primary skl1.ukl.uni-freiburg.de

Found

Primary (MNAME)
skl1.ukl.uni-freiburg.de
Contact (RNAME)
hostmaster.uniklinik-freiburg.de
Serial
689873552
Refresh / retry
1200 s / 180 s
Expire
1209600 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
dns1.belwue.de (129.143.2.10)689873552
dns1.belwue.de (2001:7c0::53:10)689873552
dns3.belwue.de (129.143.253.133)689873552
dns3.belwue.de (2001:7c0:0:253::133)689873552
dns5.belwue.de (129.143.4.5)689873552
dns5.belwue.de (2001:7c0::53:5)689873552
skl1.ukl.uni-freiburg.de (193.196.199.1)689873552

Checks

  • ✓ Serial 689873552 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 20m, retry 3m, expire 14d, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver skl1.ukl.uni-freiburg.de is one of the listed nameservers.
  • ✓ Contact hostmaster@uniklinik-freiburg.de #25
    The SOA RNAME hostmaster.uniklinik-freiburg.de means hostmaster@uniklinik-freiburg.de.
  • ✓ Counter serial #26
    The serial 689873552 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

12 records at the apex

Found

Read from
129.143.2.10:53
TypeValueTTL
SOAskl1.ukl.uni-freiburg.de. hostmaster.uniklinik-freiburg.de. 689873552 1200 180 1209600 36003600
NSdns3.belwue.de.3600
NSdns1.belwue.de.3600
NSskl1.ukl.uni-freiburg.de.3600
NSdns5.belwue.de.3600
A99.83.231.1483600
MX10000 c1711.mx.srv.dfn.de.3600
MX10000 a1711.mx.srv.dfn.de.3600
MX10000 b1711.mx.srv.dfn.de.3600
TXT"HARICA-wj3nZiXyWOwy4U6Hfso"3600
TXT"v=spf1 a mx include:spf.mailsupport.dfn.de ~all"3600
TXT"HARICA-eZlCUUxlrL8uTuKIxXN"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.
  • i
    Wildcard record
    A random name under the zone resolves, so there is a wildcard (*) record. Typos and non-existent hosts resolve too, which can confuse mail and certificate checks.
    #34
  • 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