fiz-karlsruhe.de

Checked 21 October 2026, 22:30 UTC · via 8.8.8.8
✗Problems found
20 passed 3 warnings 2 failed 4 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

warn

dns-3.dfn.de, dns1.fiz-karlsruhe.de, dns2.fiz-karlsruhe.de, xlink1.xlink.net

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-3.dfn.de, dns1.fiz-karlsruhe.de, dns2.fiz-karlsruhe.de, xlink1.xlink.net
NS in the zone
dns-3.dfn.de, dns1.fiz-karlsruhe.de, dns2.fiz-karlsruhe.de
NameserverAddressesNetwork (AS)Glue
dns-3.dfn.de193.174.75.58 2001:638:d:b103::1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
dns1.fiz-karlsruhe.de141.66.18.17AS13040 ASN-FIZ - FIZ Karlsruhe - Leibniz-Institut fuer Informationsinfrastruktur GmbH, DE141.66.18.17
dns2.fiz-karlsruhe.de141.66.19.17AS13040 ASN-FIZ - FIZ Karlsruhe - Leibniz-Institut fuer Informationsinfrastruktur GmbH, DE141.66.19.17
xlink1.xlink.net (parent only)194.45.97.99AS6724 STRATO - Strato GmbH, DE-

Checks

  • ✓ 4 nameservers #6
    Delegated to dns-3.dfn.de, dns1.fiz-karlsruhe.de, dns2.fiz-karlsruhe.de, xlink1.xlink.net.
  • !
    NS sets differ
    The nameservers at the parent and in the zone should be the same. Only at the parent: xlink1.xlink.net. dns-3.dfn.de, dns1.fiz-karlsruhe.de, dns2.fiz-karlsruhe.de report NS dns-3.dfn.de dns1.fiz-karlsruhe.de dns2.fiz-karlsruhe.de.
    #7
  • ✓ Glue present and correct #8
    Glue is published for the nameservers inside the zone: dns1.fiz-karlsruhe.de, dns2.fiz-karlsruhe.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 4 IPv4 /24s and 1 IPv6 /48.
  • ✓ 3 autonomous systems #11
    The nameservers are spread over: AS13040 (ASN-FIZ - FIZ Karlsruhe - Leibniz-Institut fuer Informationsinfrastruktur GmbH, DE): 2 addresses; AS6724 (STRATO - Strato GmbH, DE): 1 address; AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE): 2 addresses.
  • ✓ Nameserver names under 2 TLDs #12
    Nameserver names use the TLDs .de, .net.
  • i
    Partly IPv6
    These nameservers have no IPv6 address: dns1.fiz-karlsruhe.de, dns2.fiz-karlsruhe.de, xlink1.xlink.net.
    #13

Nameservers

fail

4 of 5 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns-3.dfn.de 193.174.75.58NOERROR, 10 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 2001:638:d:b103::1NOERROR, 8 ms, authoritativenoyes / yesrefused0
dns1.fiz-karlsruhe.de 141.66.18.17NOERROR, 7 ms, authoritativenoyes / yesrefused-
dns2.fiz-karlsruhe.de 141.66.19.17NOERROR, 6 ms, authoritativenoyes / yesrefused-
xlink1.xlink.net 194.45.97.99REFUSED, 13 ms, NOT authoritativenono / yesrefused9.9.5-9+deb8u19-Debian

Checks

  • ✓ All respond #14
    All 5 nameserver addresses answered.
  • ✗
    Lame delegation
    These nameservers don't answer authoritatively for the zone, so resolvers ignore them: xlink1.xlink.net (194.45.97.99): REFUSED, authoritative=false.
    #15
  • ✓ 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: xlink1.xlink.net: "9.9.5-9+deb8u19-Debian". Hide or replace the version string.
    #17
  • ✓ Zone transfers refused #18
    No nameserver allows a zone transfer to the public.
  • ✗
    No DNS over TCP
    DNS over TCP is required (RFC 7766); without it, large answers such as DNSSEC responses fail. Not answering over TCP: xlink1.xlink.net (194.45.97.99): .
    #19
  • ✓ EDNS supported #20
    All nameservers support EDNS(0).
  • ✓ Public addresses #21
    All nameserver addresses are publicly routable.

SOA

pass

serial 2006093394 · primary dns1.fiz-karlsruhe.de

Found

Primary (MNAME)
dns1.fiz-karlsruhe.de
Contact (RNAME)
hostmaster.fiz-karlsruhe.de
Serial
2006093394
Refresh / retry
10800 s / 3600 s
Expire
2332800 s
Negative TTL
900 s

Serial per nameserver

NameserverSerial
dns-3.dfn.de (193.174.75.58)2006093394
dns-3.dfn.de (2001:638:d:b103::1)2006093394
dns1.fiz-karlsruhe.de (141.66.18.17)2006093394
dns2.fiz-karlsruhe.de (141.66.19.17)2006093394

Checks

  • ✓ Serial 2006093394 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 3h, retry 1h, expire 27d, negative TTL 15m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver dns1.fiz-karlsruhe.de is one of the listed nameservers.
  • ✓ Contact hostmaster@fiz-karlsruhe.de #25
    The SOA RNAME hostmaster.fiz-karlsruhe.de means hostmaster@fiz-karlsruhe.de.
  • ✓ Timestamp serial #26
    The serial 2006093394 is a Unix timestamp (2033-07-27 16:09 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

13 records at the apex

Found

Read from
193.174.75.58:53
TypeValueTTL
SOAdns1.fiz-karlsruhe.de. hostmaster.fiz-karlsruhe.de. 2006093394 10800 3600 2332800 90028800
NSdns2.fiz-karlsruhe.de.28800
NSdns-3.dfn.de.28800
NSdns1.fiz-karlsruhe.de.28800
A141.66.193.5828800
MX20 mailgw.fiz-karlsruhe.de.28800
MX30 mailgate2.fiz-karlsruhe.de.28800
TXT"cisco-ci-domain-verification=2a729bfe4d0bc56cc0cd827c975206e1f89e5b2ea034a92ba9c6b62b6057cf12"28800
TXT"MS=37AE0F49BF785FAF5CEEF9E599048C527BD2FF11"28800
TXT"HARICA-reL9EMfMMPu5CKN8PkI"28800
TXT"v=spf1 ip4:141.66.0.0/16 include:spf.crsend.com -all"28800
TXT"amazonses:QS0Ib52vdoshvWdYwRVceYcHLXGhSHR2+9OlUKw9vDM="28800
TXT"adobe-idp-site-verification=251f433b8ec5c1b0e61a0ecc32cf601c04d98f143bc05e74dbc6f49460267524"28800

Checks

  • ✓ TTLs within range #32
    TTLs: A 8h, MX 8h, NS 8h. The NS TTL at the parent is 1d and in the zone 8h; 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