franken.de

Checked 21 October 2026, 22:31 UTC · via 8.8.8.8
✗Problems found
19 passed 2 warnings 1 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

arbi.informatik.uni-oldenburg.de, dns.franken.de, ns.rrze.uni-erlangen.de, secondary.rrze.uni-erlangen.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
arbi.informatik.uni-oldenburg.de, dns.franken.de, ns.rrze.uni-erlangen.de, secondary.rrze.uni-erlangen.de
NS in the zone
arbi.informatik.uni-oldenburg.de, dns.franken.de, ns.rrze.uni-erlangen.de, secondary.rrze.uni-erlangen.de
NameserverAddressesNetwork (AS)Glue
arbi.informatik.uni-oldenburg.de134.106.1.7AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE134.106.1.7
dns.franken.de193.175.24.33AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE193.175.24.33
ns.rrze.uni-erlangen.de131.188.3.2 131.188.0.50 2001:638:a000:1055:53::1 2001:638:a000:1001:53::1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
secondary.rrze.uni-erlangen.de131.188.3.4 131.188.0.52 2001:638:a000:1055:53::3 2001:638:a000:1001:53::3AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-

Checks

  • ✓ 4 nameservers #6
    Delegated to arbi.informatik.uni-oldenburg.de, dns.franken.de, ns.rrze.uni-erlangen.de, secondary.rrze.uni-erlangen.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: dns.franken.de.
  • ✓ 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 2001:638:a000::/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 (AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., 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
  • i
    Partly IPv6
    These nameservers have no IPv6 address: arbi.informatik.uni-oldenburg.de, dns.franken.de.
    #13

Nameservers

fail

10 of 10 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
arbi.informatik.uni-oldenburg.de 134.106.1.7NOERROR, 22 ms, authoritativenoyes / yesrefused9.18.21
dns.franken.de 193.175.24.33NOERROR, 7 ms, authoritativenoyes / yesALLOWED (4068 records)9.18.49-1~deb12u1-Debian
ns.rrze.uni-erlangen.de 131.188.3.2NOERROR, 7 ms, authoritativenoyes / yesrefused-
ns.rrze.uni-erlangen.de 131.188.0.50NOERROR, 7 ms, authoritativenoyes / yesrefused-
ns.rrze.uni-erlangen.de 2001:638:a000:1055:53::1NOERROR, 10 ms, authoritativenoyes / yesrefused-
ns.rrze.uni-erlangen.de 2001:638:a000:1001:53::1NOERROR, 10 ms, authoritativenoyes / yesrefused-
secondary.rrze.uni-erlangen.de 131.188.3.4NOERROR, 7 ms, authoritativenoyes / yesrefused-
secondary.rrze.uni-erlangen.de 131.188.0.52NOERROR, 7 ms, authoritativenoyes / yesrefused-
secondary.rrze.uni-erlangen.de 2001:638:a000:1055:53::3NOERROR, 7 ms, authoritativenoyes / yesrefused-
secondary.rrze.uni-erlangen.de 2001:638:a000:1001:53::3NOERROR, 7 ms, authoritativenoyes / yesrefused-

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: arbi.informatik.uni-oldenburg.de: "9.18.21"; dns.franken.de: "9.18.49-1~deb12u1-Debian". Hide or replace the version string.
    #17
  • ✗
    Zone transfer allowed
    These nameservers send the complete zone to anyone who asks (AXFR), exposing all host names: dns.franken.de (193.175.24.33): 4068 records. Restrict zone transfers to your secondary servers.
    #18
  • ✓ 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 2026100801 · primary dns.franken.de

Found

Primary (MNAME)
dns.franken.de
Contact (RNAME)
dnsmaster.franken.de
Serial
2026100801
Refresh / retry
3600 s / 1800 s
Expire
1209600 s
Negative TTL
20000 s

Serial per nameserver

NameserverSerial
arbi.informatik.uni-oldenburg.de (134.106.1.7)2026100801
dns.franken.de (193.175.24.33)2026100801
ns.rrze.uni-erlangen.de (131.188.3.2)2026100801
ns.rrze.uni-erlangen.de (131.188.0.50)2026100801
ns.rrze.uni-erlangen.de (2001:638:a000:1055:53::1)2026100801
ns.rrze.uni-erlangen.de (2001:638:a000:1001:53::1)2026100801
secondary.rrze.uni-erlangen.de (131.188.3.4)2026100801
secondary.rrze.uni-erlangen.de (131.188.0.52)2026100801
secondary.rrze.uni-erlangen.de (2001:638:a000:1055:53::3)2026100801
secondary.rrze.uni-erlangen.de (2001:638:a000:1001:53::3)2026100801

Checks

  • ✓ Serial 2026100801 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 1h, retry 30m, expire 14d, negative TTL 5h33m20s.
  • ✓ Primary is a public nameserver #24
    The primary nameserver dns.franken.de is one of the listed nameservers.
  • ✓ Contact dnsmaster@franken.de #25
    The SOA RNAME dnsmaster.franken.de means dnsmaster@franken.de.
  • ✓ Date-based serial #26
    The serial 2026100801 follows the YYYYMMDDnn convention (2026-10-08).

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
134.106.1.7:53
TypeValueTTL
SOAdns.franken.de. dnsmaster.franken.de. 2026100801 3600 1800 1209600 200003600
NSdns.franken.de.3600
NSsecondary.rrze.uni-erlangen.de.3600
NSns.rrze.uni-erlangen.de.3600
NSarbi.informatik.uni-oldenburg.de.3600
A193.175.24.203600
MX20 priscilla.franken.de.300
MX10 lists.franken.de.300
TXT"v=spf1 mx include:spf-n.franken.de include:spf-r.franken.de include:spf-wue.franken.de ~all"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 1h, MX 5m, 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.
  • ✓ 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