gdv.de

Checked 21 October 2026, 22:32 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

warn

ns0.de.colt.net, ns8.colt.net

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
ns0.de.colt.net, ns8.colt.net
NS in the zone
ns0.de.colt.net, ns8.colt.net
NameserverAddressesNetwork (AS)Glue
ns0.de.colt.net212.74.78.55AS8220 COLT - COLT Technology Services Group Limited, GB-
ns8.colt.net84.14.241.53AS8220 COLT - COLT Technology Services Group Limited, GB-

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: ns0.de.colt.net, ns8.colt.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 0 IPv6 /48s.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS8220 (COLT - COLT Technology Services Group Limited, GB): 2 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 .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
  • !
    No IPv6
    None of the nameservers has an IPv6 address, so IPv6-only resolvers can't reach them.
    #13

Nameservers

info

2 of 2 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns0.de.colt.net 212.74.78.55NOERROR, 4 ms, authoritativenoyes / yesrefusedColt
ns8.colt.net 84.14.241.53NOERROR, 12 ms, authoritativenoyes / yesrefusedColt

Checks

  • ✓ All respond #14
    All 2 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: ns0.de.colt.net: "Colt"; ns8.colt.net: "Colt".
    #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 2026101900 · primary ns0.de.colt.net

Found

Primary (MNAME)
ns0.de.colt.net
Contact (RNAME)
dns-requests.colt.net
Serial
2026101900
Refresh / retry
43200 s / 7200 s
Expire
1209600 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
ns0.de.colt.net (212.74.78.55)2026101900
ns8.colt.net (84.14.241.53)2026101900

Checks

  • ✓ Serial 2026101900 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 12h, retry 2h, expire 14d, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns0.de.colt.net is one of the listed nameservers.
  • ✓ Contact dns-requests@colt.net #25
    The SOA RNAME dns-requests.colt.net means dns-requests@colt.net.
  • ✓ Date-based serial #26
    The serial 2026101900 follows the YYYYMMDDnn convention (2026-10-19).

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

12 records at the apex

Found

Read from
212.74.78.55:53
TypeValueTTL
SOAns0.de.colt.net. dns-requests.colt.net. 2026101900 43200 7200 1209600 8640086400
NSns8.colt.net.86400
NSns0.de.colt.net.86400
A167.235.109.15386400
MX100 smail1.gdv.org.86400
MX100 smail.gdv.org.86400
TXT"jamf-site-verification=ztSDTuurtpUM_gJ_jUVJSQ"60
TXT"openai-domain-verification=dv-kT5maNJNmjik4aq1B40UFspQ"60
TXT"google-site-verification=eVeCYsXVGVPnE1s4IZUnl_g7k6LENsmXD8jPZgeQWMk"60
TXT"MS=ms51644779"60
TXT"v=spf1 mx ip4:217.110.75.0/24 ip4:185.22.149.0/24 ip4:144.76.32.198 ip4:144.76.32.199 ip4:188.34.161.228/32 ip4:116.202.104.111/32 ip4:23.88.35.177/32 ip4:212.34.64.185 include:spf.crsend.com include:spf.codepiraten.com include:spf.tixxt.com include:spf.m" "ailjet.com include:eur.pb-dynmktge.com a:gdc-smx.connect.guidecom.de ~all"60
TXT"_yp1g21yqjaaijr36yk3ablcwalrzju0"60

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