friedrichshafen.de

Checked 21 October 2026, 22:31 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

auth01.ns.td-fn.net, auth02.ns.td-fn.net

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
auth01.ns.td-fn.net, auth02.ns.td-fn.net
NS in the zone
auth01.ns.td-fn.net, auth02.ns.td-fn.net
NameserverAddressesNetwork (AS)Glue
auth01.ns.td-fn.net82.98.67.141 2a02:2e0:401:7e1e:da7a::aAS12306 PLUSLINE - Plus.line AG, DE AS12306 PLUSLINE - Plus.line AG, DE-
auth02.ns.td-fn.net217.24.194.130 2a02:590:1:1::130AS21263 TELEDATA-AS - TeleData GmbH, DE AS21263 TELEDATA-AS - TeleData GmbH, DE-

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: auth01.ns.td-fn.net, auth02.ns.td-fn.net.
    #6
  • ✓ 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 2 IPv4 /24s and 2 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS12306 (PLUSLINE - Plus.line AG, DE): 2 addresses; AS21263 (TELEDATA-AS - TeleData GmbH, DE): 2 addresses.
  • i
    All nameserver names under .net
    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

info

4 of 4 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
auth01.ns.td-fn.net 82.98.67.141NOERROR, 4 ms, authoritativenoyes / yesrefused[SECURED]
auth01.ns.td-fn.net 2a02:2e0:401:7e1e:da7a::aNOERROR, 4 ms, authoritativenoyes / yesrefused[SECURED]
auth02.ns.td-fn.net 217.24.194.130NOERROR, 13 ms, authoritativenoyes / yesrefused[SECURED]
auth02.ns.td-fn.net 2a02:590:1:1::130NOERROR, 12 ms, authoritativenoyes / yesrefused[SECURED]

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: auth01.ns.td-fn.net: "[SECURED]"; auth02.ns.td-fn.net: "[SECURED]".
    #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

warn

serial 2026081801 · primary auth02.ns.td-fn.net

Found

Primary (MNAME)
auth02.ns.td-fn.net
Contact (RNAME)
hostmaster.td-fn.net
Serial
2026081801
Refresh / retry
3600 s / 7200 s
Expire
3600 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
auth01.ns.td-fn.net (82.98.67.141)2026081801
auth01.ns.td-fn.net (2a02:2e0:401:7e1e:da7a::a)2026081801
auth02.ns.td-fn.net (217.24.194.130)2026081801
auth02.ns.td-fn.net (2a02:590:1:1::130)2026081801

Checks

  • ✓ Serial 2026081801 everywhere #22
    All nameservers serve the same version of the zone.
  • !
    Unusual SOA timers
    retry 2h should be shorter than refresh 1h; expire 1h is shorter than 7d; secondaries stop answering too soon when the primary is down; expire 1h must be longer than refresh + retry. Current values: refresh 1h, retry 2h, expire 1h, negative TTL 1h.
    #23
  • ✓ Primary is a public nameserver #24
    The primary nameserver auth02.ns.td-fn.net is one of the listed nameservers.
  • ✓ Contact hostmaster@td-fn.net #25
    The SOA RNAME hostmaster.td-fn.net means hostmaster@td-fn.net.
  • ✓ Date-based serial #26
    The serial 2026081801 follows the YYYYMMDDnn convention (2026-08-18).

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

13 records at the apex

Found

Read from
82.98.67.141:53
TypeValueTTL
SOAauth02.ns.td-fn.net. hostmaster.td-fn.net. 2026081801 3600 7200 3600 360086400
NSauth01.ns.td-fn.net.86400
NSauth02.ns.td-fn.net.86400
A193.111.102.9286400
MX10 mail02.friedrichshafen.de.86400
MX10 mail01.friedrichshafen.de.86400
TXT"google-site-verification=-t2BPmiDN05KZKxDwk4Q0TXB_lBUraTLjMD4aj7u3pA"86400
TXT"v=spf1 ip4:217.24.204.40 ip4:217.24.204.41 ip4:10.204.160.158 a:mail01.friedrichshafen.de a:mail02.friedrichshafen.de"86400
TXT"apple-domain-verification=JFh3wdEq5kWCYt6Z"86400
TXT"apple-domain-verification=Rooxn9sTjgb6hlhd"86400
TXT"MS=ADAC2202A8811B91D578A3CEC181362B89D51236"86400
TXT"lnk_sndcpt_b3cae57afd885270268ddc09adfa7a8d"86400
TXT"swisssign-check=IbpIovi2oll_BMBObDct_oqC93s"86400

Checks

  • ✓ TTLs within range #32
    TTLs: A 1d, MX 1d, NS 1d.
  • ✓ 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