cttue.de

Checked 21 October 2026, 22:11 UTC · via 8.8.8.8
!Passed with warnings
19 passed 3 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

root-dns.netcup.net, second-dns.netcup.net, third-dns.netcup.net

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
root-dns.netcup.net, second-dns.netcup.net, third-dns.netcup.net
NS in the zone
root-dns.netcup.net, second-dns.netcup.net, third-dns.netcup.net
NameserverAddressesNetwork (AS)Glue
root-dns.netcup.net46.38.225.225 2a03:4000:0:1::e1e1AS197540 netcup-AS - netcup GmbH, DE AS197540 netcup-AS - netcup GmbH, DE-
second-dns.netcup.net37.221.199.199 2a03:4000:2:24b::c7c7AS197540 netcup-AS - netcup GmbH, DE AS197540 netcup-AS - netcup GmbH, DE-
third-dns.netcup.net188.68.63.68 2a03:4001:0:106::3f44AS197540 netcup-AS - netcup GmbH, DE AS197540 netcup-AS - netcup GmbH, DE-

Checks

  • ✓ 3 nameservers #6
    Delegated to root-dns.netcup.net, second-dns.netcup.net, third-dns.netcup.net.
  • ✓ 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 3 IPv4 /24s and 3 IPv6 /48s.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS197540 (netcup-AS - netcup GmbH, DE): 6 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
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

info

6 of 6 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
root-dns.netcup.net 46.38.225.225NOERROR, 1 ms, authoritativenoyes / yesrefused[SECURED]
root-dns.netcup.net 2a03:4000:0:1::e1e1NOERROR, 1 ms, authoritativenoyes / yesrefused[SECURED]
second-dns.netcup.net 37.221.199.199NOERROR, 1 ms, authoritativenoyes / yesrefused[SECURED]
second-dns.netcup.net 2a03:4000:2:24b::c7c7NOERROR, 1 ms, authoritativenoyes / yesrefused[SECURED]
third-dns.netcup.net 188.68.63.68NOERROR, 4 ms, authoritativenoyes / yesrefused[SECURED]
third-dns.netcup.net 2a03:4001:0:106::3f44NOERROR, 4 ms, authoritativenoyes / yesrefused[SECURED]

Checks

  • ✓ All respond #14
    All 6 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: root-dns.netcup.net: "[SECURED]"; second-dns.netcup.net: "[SECURED]"; third-dns.netcup.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 2026072772 · primary root-dns.netcup.net

Found

Primary (MNAME)
root-dns.netcup.net
Contact (RNAME)
dnsadmin.netcup.net
Serial
2026072772
Refresh / retry
28800 s / 7200 s
Expire
1209600 s
Negative TTL
180 s

Serial per nameserver

NameserverSerial
root-dns.netcup.net (46.38.225.225)2026072772
root-dns.netcup.net (2a03:4000:0:1::e1e1)2026072772
second-dns.netcup.net (37.221.199.199)2026072772
second-dns.netcup.net (2a03:4000:2:24b::c7c7)2026072772
third-dns.netcup.net (188.68.63.68)2026072772
third-dns.netcup.net (2a03:4001:0:106::3f44)2026072772

Checks

  • ✓ Serial 2026072772 everywhere #22
    All nameservers serve the same version of the zone.
  • !
    Unusual SOA timers
    negative caching TTL (minimum) 3m is outside 5m–1d (RFC 2308 recommends 1–3 hours). Current values: refresh 8h, retry 2h, expire 14d, negative TTL 3m.
    #23
  • ✓ Primary is a public nameserver #24
    The primary nameserver root-dns.netcup.net is one of the listed nameservers.
  • ✓ Contact dnsadmin@netcup.net #25
    The SOA RNAME dnsadmin.netcup.net means dnsadmin@netcup.net.
  • ✓ Date-based serial #26
    The serial 2026072772 follows the YYYYMMDDnn convention (2026-07-27).

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

warn

10 records at the apex

Found

Read from
46.38.225.225:53
TypeValueTTL
SOAroot-dns.netcup.net. dnsadmin.netcup.net. 2026072772 28800 7200 1209600 180180
NSsecond-dns.netcup.net.180
NSroot-dns.netcup.net.180
NSthird-dns.netcup.net.180
A202.61.232.82180
AAAA2a03:4000:61:255e::17:6550180
MX10 mail.cttue.de.180
MX50 mxe854.netcup.net.180
TXT"google-site-verification=aqulONMJZMg6tgGBs3MhdIZqdDS2Dd68ZQc956GZazA"180
TXT"v=spf1 mx a include:_spf.webhosting.systems ~all"180

Checks

  • !
    Very low TTLs
    These records have a TTL below 5m, causing extra queries and slower lookups: A (3m), AAAA (3m), MX (3m), NS (3m). Low TTLs are useful just before a planned change. The NS TTL at the parent is 1d and in the zone 3m; resolvers may use either.
    #32
  • ✓ 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