zalf.de

Checked 22 October 2026, 01:10 UTC · via 8.8.8.8
✗Problems found
19 passed 1 warning 1 failed 8 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

deneb.dfn.de, wany.zalf.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
deneb.dfn.de, wany.zalf.de
NS in the zone
deneb.dfn.de, wany.zalf.de
NameserverAddressesNetwork (AS)Glue
deneb.dfn.de192.76.176.9 2001:638:800:1::9AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
wany.zalf.de193.175.152.108AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE193.175.152.108

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: deneb.dfn.de, wany.zalf.de.
    #6
  • ✓ 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: wany.zalf.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 2 IPv4 /24s and 1 IPv6 /48.
  • 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): 3 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: wany.zalf.de.
    #13

Nameservers

fail

2 of 3 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
deneb.dfn.de 192.76.176.9NOERROR, 14 ms, authoritativenoyes / yesrefused0
deneb.dfn.de 2001:638:800:1::9NOERROR, 14 ms, authoritativenoyes / yesrefused0
wany.zalf.de 193.175.152.108no responsenono / no--

Checks

  • ✗
    Nameservers not responding
    These addresses did not answer, so resolvers waste time on timeouts: wany.zalf.de (193.175.152.108): read udp 46.225.38.91:43392->193.175.152.108:53: i/o timeout.
    #14
  • ✓ 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: deneb.dfn.de: "0".
    #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 2026101501 · primary wany.zalf.de

Found

Primary (MNAME)
wany.zalf.de
Contact (RNAME)
rz.zalf.de
Serial
2026101501
Refresh / retry
21600 s / 3600 s
Expire
2419200 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
deneb.dfn.de (192.76.176.9)2026101501
deneb.dfn.de (2001:638:800:1::9)2026101501

Checks

  • ✓ Serial 2026101501 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 6h, retry 1h, expire 28d, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver wany.zalf.de is one of the listed nameservers.
  • ✓ Contact rz@zalf.de #25
    The SOA RNAME rz.zalf.de means rz@zalf.de.
  • ✓ Date-based serial #26
    The serial 2026101501 follows the YYYYMMDDnn convention (2026-10-15).

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
192.76.176.9:53
TypeValueTTL
SOAwany.zalf.de. rz.zalf.de. 2026101501 21600 3600 2419200 8640086400
NSdeneb.dfn.de.86400
NSwany.zalf.de.86400
A193.175.153.23586400
MX10 zalf-de.mail.protection.outlook.com.86400
TXT"MS=A0F82A1A7185B0238F0D315C497A9F9EE39BBA49"86400
TXT"v=spf1 mx a:srv-it-sophos.zalf.de a:email.zalf.de a:outlook.zalf.de a:reddoxx.zalf.de ip4:193.175.153.118 include:newsmailservice.de include:spf.protection.outlook.com ~all"86400
TXT"MS=ms92175064"86400
TXT"google-site-verification=6r7GQKPZJYglTgsdmfkYRO6C-ZftwJQ_EQJ1lIN2_o0"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.
  • ✓ 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