erf.de

Checked 21 October 2026, 22:19 UTC · via 8.8.8.8
!Passed with warnings
22 passed 2 warnings 0 failed 5 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

cleo.ns.cloudflare.com, serena.ns.cloudflare.com

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
cleo.ns.cloudflare.com, serena.ns.cloudflare.com
NS in the zone
cleo.ns.cloudflare.com, serena.ns.cloudflare.com
NameserverAddressesNetwork (AS)Glue
cleo.ns.cloudflare.com172.64.33.89 108.162.193.89 173.245.59.89 2803:f800:50::6ca2:c159 2a06:98c1:50::ac40:2159 2606:4700:58::adf5:3b59AS13335 CLOUDFLARENET - Cloudflare, Inc., US AS13335 CLOUDFLARENET - Cloudflare, Inc., US AS13335 CLOUDFLARENET - Cloudflare, Inc., US AS13335 CLOUDFLARENET - Cloudflare, Inc., US AS13335 CLOUDFLARENET - Cloudflare, Inc., US AS13335 CLOUDFLARENET - Cloudflare, Inc., US-
serena.ns.cloudflare.com172.64.32.220 108.162.192.220 173.245.58.220 2a06:98c1:50::ac40:20dc 2803:f800:50::6ca2:c0dc 2606:4700:50::adf5:3adcAS13335 CLOUDFLARENET - Cloudflare, Inc., US AS13335 CLOUDFLARENET - Cloudflare, Inc., US AS13335 CLOUDFLARENET - Cloudflare, Inc., US AS13335 CLOUDFLARENET - Cloudflare, Inc., US AS13335 CLOUDFLARENET - Cloudflare, Inc., US AS13335 CLOUDFLARENET - Cloudflare, Inc., US-

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: cleo.ns.cloudflare.com, serena.ns.cloudflare.com.
    #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 6 IPv4 /24s and 4 IPv6 /48s.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS13335 (CLOUDFLARENET - Cloudflare, Inc., US): 12 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 .com
    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

warn

12 of 12 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
cleo.ns.cloudflare.com 172.64.33.89NOERROR, 14 ms, authoritativenoyes / yesrefused2026.10.2
cleo.ns.cloudflare.com 108.162.193.89NOERROR, 15 ms, authoritativenoyes / yesrefused2026.10.2
cleo.ns.cloudflare.com 173.245.59.89NOERROR, 15 ms, authoritativenoyes / yesrefused2026.10.2
cleo.ns.cloudflare.com 2803:f800:50::6ca2:c159NOERROR, 19 ms, authoritativenoyes / yesrefused2026.10.2
cleo.ns.cloudflare.com 2a06:98c1:50::ac40:2159NOERROR, 16 ms, authoritativenoyes / yesrefused2026.10.2
cleo.ns.cloudflare.com 2606:4700:58::adf5:3b59NOERROR, 16 ms, authoritativenoyes / yesrefused2026.10.2
serena.ns.cloudflare.com 172.64.32.220NOERROR, 14 ms, authoritativenoyes / yesrefused2026.10.2
serena.ns.cloudflare.com 108.162.192.220NOERROR, 15 ms, authoritativenoyes / yesrefused2026.10.2
serena.ns.cloudflare.com 173.245.58.220NOERROR, 14 ms, authoritativenoyes / yesrefused2026.10.2
serena.ns.cloudflare.com 2a06:98c1:50::ac40:20dcNOERROR, 15 ms, authoritativenoyes / yesrefused2026.10.2
serena.ns.cloudflare.com 2803:f800:50::6ca2:c0dcNOERROR, 16 ms, authoritativenoyes / yesrefused2026.10.2
serena.ns.cloudflare.com 2606:4700:50::adf5:3adcNOERROR, 16 ms, authoritativenoyes / yesrefused2026.10.2

Checks

  • ✓ All respond #14
    All 12 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.
  • !
    Software version disclosed
    These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: cleo.ns.cloudflare.com: "2026.10.2"; serena.ns.cloudflare.com: "2026.10.2". Hide or replace the version string.
    #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 2418099073 · primary cleo.ns.cloudflare.com

Found

Primary (MNAME)
cleo.ns.cloudflare.com
Contact (RNAME)
dns.cloudflare.com
Serial
2418099073
Refresh / retry
10000 s / 2400 s
Expire
604800 s
Negative TTL
1800 s

Serial per nameserver

NameserverSerial
cleo.ns.cloudflare.com (172.64.33.89)2418099073
cleo.ns.cloudflare.com (108.162.193.89)2418099073
cleo.ns.cloudflare.com (173.245.59.89)2418099073
cleo.ns.cloudflare.com (2803:f800:50::6ca2:c159)2418099073
cleo.ns.cloudflare.com (2a06:98c1:50::ac40:2159)2418099073
cleo.ns.cloudflare.com (2606:4700:58::adf5:3b59)2418099073
serena.ns.cloudflare.com (172.64.32.220)2418099073
serena.ns.cloudflare.com (108.162.192.220)2418099073
serena.ns.cloudflare.com (173.245.58.220)2418099073
serena.ns.cloudflare.com (2a06:98c1:50::ac40:20dc)2418099073
serena.ns.cloudflare.com (2803:f800:50::6ca2:c0dc)2418099073
serena.ns.cloudflare.com (2606:4700:50::adf5:3adc)2418099073

Checks

  • ✓ Serial 2418099073 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 2h46m40s, retry 40m, expire 7d, negative TTL 30m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver cleo.ns.cloudflare.com is one of the listed nameservers.
  • ✓ Contact dns@cloudflare.com #25
    The SOA RNAME dns.cloudflare.com means dns@cloudflare.com.
  • ✓ Timestamp serial #26
    The serial 2418099073 is a Unix timestamp (2046-08-17 06:11 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

pass

36 records at the apex

Found

Read from
172.64.33.89:53
TypeValueTTL
SOAcleo.ns.cloudflare.com. dns.cloudflare.com. 2418099073 10000 2400 604800 18001800
NScleo.ns.cloudflare.com.86400
NSserena.ns.cloudflare.com.86400
A172.67.71.244300
A104.26.0.175300
A104.26.1.175300
AAAA2606:4700:20::681a:af300
AAAA2606:4700:20::681a:1af300
AAAA2606:4700:20::ac43:47f4300
MX0 erf-de.mail.protection.outlook.com.300
TXT"6TX77poa1CUkctBYjEDxEPt12W58r4Cchlm5xYjhAM/zoNg7ouzDFkL5iCO0Y9nEtR05wW8RGJWnSOyVw0iF4w=="300
TXT"MS=ms31202516"300
TXT"anthropic-domain-verification-wxctgw=iOSmhET5uIDPHTJetTMMjHLOP"300
TXT"apple-domain-verification=SDA3VRjCS9bA2QAs"300
TXT"canva-site-verification=CQbVyYUTtZZOBEJnSfQy1w"300
TXT"d365mktkey=2kk8oxs445uskdi2qoi9kedr1"300
TXT"d365mktkey=dWMY0liLjjZHWZIi94gbbw2C2GRbpJLlb0Nx5MCE60kx"300
TXT"d365mktkey=hVyVOmS5zLvrX8FFZ4fFCx4sRHkLLzGQLNMP7Wjdc64x"300
TXT"google-site-verification=9YZ0uHyF_hfm6AAiPVQkct_E0UgiRtUWy16iZXbYg_U"300
TXT"lw=635feb61476501a50a9afd00"300
TXT"stripe-verification=f106283b2a50192b586cd3861d330fc8cf41ff71c9b1d10d394f6941e54c1de0"300
TXT"v=spf1 a mx ip4:195.248.89.10 ip4:195.248.89.60 ip4:109.91.166.37 ip4:46.4.4.115 ip4:168.119.91.212 ip4:46.229.46.39 ip4:212.162.53.160 ip4:46.229.46.157 include:spf.protection.outlook.com include:spf.emailsys.net include:mailgun.org -all"300
CAA0 issue "certum.pl"300
CAA0 issue "comodoca.com"300
CAA0 issue "digicert.com; cansignhttpexchanges=yes"300
CAA0 issue "letsencrypt.org"300
CAA0 issue "pki.goog; cansignhttpexchanges=yes"300
CAA0 issue "sectigo.com"300
CAA0 issue "ssl.com"300
CAA0 issuewild "certum.pl"300
CAA0 issuewild "comodoca.com"300
CAA0 issuewild "digicert.com; cansignhttpexchanges=yes"300
CAA0 issuewild "letsencrypt.org"300
CAA0 issuewild "pki.goog; cansignhttpexchanges=yes"300
CAA0 issuewild "sectigo.com"300
CAA0 issuewild "ssl.com"300

Checks

  • ✓ TTLs within range #32
    TTLs: A 5m, AAAA 5m, MX 5m, 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.
  • ✓ CAA restricts issuance #35
    Certificates may be issued by: certum.pl, comodoca.com, digicert.com, letsencrypt.org, pki.goog, sectigo.com, ssl.com.