uni-freiburg.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

info

dns0.fun.uni-freiburg.de, dns1.belwue.de, dns1.fun.uni-freiburg.de, dns3.belwue.de, dns5.belwue.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns0.fun.uni-freiburg.de, dns1.belwue.de, dns1.fun.uni-freiburg.de, dns3.belwue.de, dns5.belwue.de
NS in the zone
dns0.fun.uni-freiburg.de, dns1.belwue.de, dns1.fun.uni-freiburg.de, dns3.belwue.de, dns5.belwue.de
NameserverAddressesNetwork (AS)Glue
dns0.fun.uni-freiburg.de132.230.200.200 2001:7c0:2500:1::53:0AS553 BELWUE - Universitaet Stuttgart, DE AS553 BELWUE - Universitaet Stuttgart, DE132.230.200.200 2001:7c0:2500:1::53:0
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.fun.uni-freiburg.de132.230.201.111 2001:7c0:2500:2::53:1AS553 BELWUE - Universitaet Stuttgart, DE AS553 BELWUE - Universitaet Stuttgart, DE132.230.201.111 2001:7c0:2500:2::53:1
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 dns0.fun.uni-freiburg.de, dns1.belwue.de, dns1.fun.uni-freiburg.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: dns0.fun.uni-freiburg.de, dns1.fun.uni-freiburg.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 (AS553 (BELWUE - Universitaet Stuttgart, DE): 10 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
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

warn

10 of 10 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns0.fun.uni-freiburg.de 132.230.200.200NOERROR, 9 ms, authoritativenoyes / yesrefusedunknown
dns0.fun.uni-freiburg.de 2001:7c0:2500:1::53:0NOERROR, 8 ms, authoritativenoyes / yesrefusedunknown
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.fun.uni-freiburg.de 132.230.201.111NOERROR, 8 ms, authoritativenoyes / yesrefusedunknown
dns1.fun.uni-freiburg.de 2001:7c0:2500:2::53:1NOERROR, 10 ms, authoritativenoyes / yesrefusedunknown
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

info

serial 1190830560 · primary dhcp.fun.uni-freiburg.de

Found

Primary (MNAME)
dhcp.fun.uni-freiburg.de
Contact (RNAME)
hostmaster.rz.uni-freiburg.de
Serial
1190830560
Refresh / retry
10800 s / 3600 s
Expire
2419200 s
Negative TTL
900 s

Serial per nameserver

NameserverSerial
dns0.fun.uni-freiburg.de (132.230.200.200)1190830560
dns0.fun.uni-freiburg.de (2001:7c0:2500:1::53:0)1190830560
dns1.belwue.de (129.143.2.10)1190830560
dns1.belwue.de (2001:7c0::53:10)1190830560
dns1.fun.uni-freiburg.de (132.230.201.111)1190830560
dns1.fun.uni-freiburg.de (2001:7c0:2500:2::53:1)1190830560
dns3.belwue.de (129.143.253.133)1190830560
dns3.belwue.de (2001:7c0:0:253::133)1190830560
dns5.belwue.de (129.143.4.5)1190830560
dns5.belwue.de (2001:7c0::53:5)1190830560

Checks

  • ✓ Serial 1190830560 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 3h, retry 1h, expire 28d, negative TTL 15m.
  • i
    Hidden master
    The primary nameserver dhcp.fun.uni-freiburg.de is not listed as a nameserver: a hidden master that only feeds the public secondaries. That is a common setup; make sure it is not reachable for zone transfers from outside.
    #24
  • ✓ Contact hostmaster@rz.uni-freiburg.de #25
    The SOA RNAME hostmaster.rz.uni-freiburg.de means hostmaster@rz.uni-freiburg.de.
  • ✓ Timestamp serial #26
    The serial 1190830560 is a Unix timestamp (2007-09-26 18:16 UTC).

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

17 records at the apex

Found

Read from
132.230.200.200:53
TypeValueTTL
SOAdhcp.fun.uni-freiburg.de. hostmaster.rz.uni-freiburg.de. 1190830560 10800 3600 2419200 90086400
NSdns5.belwue.de.86400
NSdns3.belwue.de.86400
NSdns0.fun.uni-freiburg.de.86400
NSdns1.fun.uni-freiburg.de.86400
NSdns1.belwue.de.86400
A132.230.100.27600
MX10000 b1421.mx.srv.dfn.de.86400
MX10000 a1421.mx.srv.dfn.de.86400
MX10 mail.uni-freiburg.de.86400
MX10000 c1421.mx.srv.dfn.de.86400
TXT"MS=81DEE9388292FA746C934DEF6BF6AC5DCCB3D1FA"300
TXT"HARICA-odju84jqPOW6izZsY2W"300
TXT"google-site-verification=eqlVEdB0u6eYcRagQAoGlLJLBTWMuaV0XZMcDpbuUtU"300
TXT"MS=ms98325981"300
TXT"v=spf1 redirect=_spf.uni-freiburg.de"300
TXT"google-site-verification=Vmg2FTPU-8yUc5cMSy3XntSi1boVx0Q6dqplocYxn30"300

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.
  • 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