heidelberg.de

Checked 21 October 2026, 22:42 UTC · via 8.8.8.8
!Passed with warnings
20 passed 2 warnings 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.uni-heidelberg.de, dns1.belwue.de, dns3.belwue.de, dns5.belwue.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns.uni-heidelberg.de, dns1.belwue.de, dns3.belwue.de, dns5.belwue.de
NS in the zone
dns.uni-heidelberg.de, dns1.belwue.de, dns3.belwue.de, dns5.belwue.de
NameserverAddressesNetwork (AS)Glue
dns.uni-heidelberg.de129.206.100.126AS553 BELWUE - Universitaet Stuttgart, DE129.206.100.126
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

Checks

  • ✓ 4 nameservers #6
    Delegated to dns.uni-heidelberg.de, dns1.belwue.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.
  • ✓ 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: dns.uni-heidelberg.de.
    #13

Nameservers

warn

7 of 7 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns.uni-heidelberg.de 129.206.100.126NOERROR, 7 ms, authoritativenoyes / yesrefused9.11.36-RedHat-9.11.36-16.el8_10.16
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, 7 ms, authoritativenoyes / yesrefusedPowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)

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: dns.uni-heidelberg.de: "9.11.36-RedHat-9.11.36-16.el8_10.16"; 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 2025061034 · primary dns1.belwue.de

Found

Primary (MNAME)
dns1.belwue.de
Contact (RNAME)
hostmaster.belwue.de
Serial
2025061034
Refresh / retry
21600 s / 1800 s
Expire
2419200 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
dns.uni-heidelberg.de (129.206.100.126)2025061034
dns1.belwue.de (129.143.2.10)2025061034
dns1.belwue.de (2001:7c0::53:10)2025061034
dns3.belwue.de (129.143.253.133)2025061034
dns3.belwue.de (2001:7c0:0:253::133)2025061034
dns5.belwue.de (129.143.4.5)2025061034
dns5.belwue.de (2001:7c0::53:5)2025061034

Checks

  • ✓ Serial 2025061034 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 6h, retry 30m, expire 28d, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver dns1.belwue.de is one of the listed nameservers.
  • ✓ Contact hostmaster@belwue.de #25
    The SOA RNAME hostmaster.belwue.de means hostmaster@belwue.de.
  • ✓ Date-based serial #26
    The serial 2025061034 follows the YYYYMMDDnn convention (2025-06-10).

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

20 records at the apex

Found

Read from
129.206.100.126:53
TypeValueTTL
SOAdns1.belwue.de. hostmaster.belwue.de. 2025061034 21600 1800 2419200 864003600
NSdns1.belwue.de.86400
NSdns.uni-heidelberg.de.86400
NSdns5.belwue.de.86400
NSdns3.belwue.de.86400
A194.76.38.343600
MX10 mx9.kvnbw.de.3600
MX10 mx7.kvnbw.de.3600
MX10 mx8.kvnbw.de.3600
MX10 mx6.kvnbw.de.3600
TXT"apple-domain-verification=vlDGdbHlERfAMLnt"3600
TXT"abuseipdb-verification=VcvRrRmx"3600
TXT"v=spf1 include:spf.protect.kvnbw.de include:spf.protection.outlook.com -all"3600
TXT"google-site-verification=mZtmNWqhdIS2Z2xPYlpd9u8bof2MR9PXf7WAQcNmXqw"3600
TXT"MS=ms59820156"3600
TXT"google-site-verification=d5vWAVBbmpC-W0uEoNX7_hXVztsAhi8AIsMJQ_I8F5Y"3600
TXT"adobe-idp-site-verification=b57fe3c9-e605-476d-ae71-1a4c046a4f7a"3600
TXT"MS=D75FD5BBE86951FB0E163928B2D4EBB6A70B041A"3600
TXT"Stadt Heidelberg, Postfach 10 55 20, 69045 Heidelberg"3600
TXT"autodesk-domain-verification=XhCFvGn1l9D2sNzk3Cmj"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 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