realpython.com

Checked 22 October 2026, 10:25 UTC · via 8.8.8.8
!Passed with warnings
28 passed 1 warning 0 failed 6 info

Registration

info

.com generic · 1API GmbH · expires 2027-08-06

Found

TLD
.com (generic)
ICANN policies apply
yes
Registrar
1API GmbH
Registered
6 August 2012
Last changed
1 August 2026
Expires
6 August 2027
Status
client transfer prohibited
Registry nameservers
curt.ns.cloudflare.com, joan.ns.cloudflare.com
RDAP server
https://rdap.verisign.com/com/v1/

Checks

  • i
    .com is a generic TLD (gTLD)
    Generic TLD under an ICANN registry agreement: ICANN-accredited registrars, UDRP and RDAP apply.
    #1
  • ✓ TLD delegated and signed #2
    .com is delegated in the root zone and DNSSEC-signed.
  • ✓ Expires on 2027-08-06 #3
    The registration is valid until 2027-08-06 (288 days).
  • ✓ Transfer locked #4
    Registry status: client transfer prohibited.
  • ✓ Registry and delegation match #5
    The nameservers registered at the registry are the ones published in DNS.

Delegation

info

curt.ns.cloudflare.com, joan.ns.cloudflare.com

Found

Parent zone
com
Delegation from
a.gtld-servers.net (192.5.6.30)
NS at the parent
curt.ns.cloudflare.com, joan.ns.cloudflare.com
NS in the zone
curt.ns.cloudflare.com, joan.ns.cloudflare.com
NameserverAddressesNetwork (AS)Glue
curt.ns.cloudflare.com108.162.193.94 173.245.59.94 172.64.33.94 2606:4700:58::adf5:3b5e 2a06:98c1:50::ac40:215e 2803:f800:50::6ca2:c15eAS13335 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., US108.162.193.94 172.64.33.94 173.245.59.94 2606:4700:58::adf5:3b5e 2803:f800:50::6ca2:c15e 2a06:98c1:50::ac40:215e
joan.ns.cloudflare.com173.245.58.173 172.64.32.173 108.162.192.173 2803:f800:50::6ca2:c0ad 2a06:98c1:50::ac40:20ad 2606:4700:50::adf5:3aadAS13335 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., US108.162.192.173 172.64.32.173 173.245.58.173 2606:4700:50::adf5:3aad 2803:f800:50::6ca2:c0ad 2a06:98c1:50::ac40:20ad

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: curt.ns.cloudflare.com, joan.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
curt.ns.cloudflare.com 108.162.193.94NOERROR, 5 ms, authoritativenoyes / yesrefused2026.10.2
curt.ns.cloudflare.com 173.245.59.94NOERROR, 5 ms, authoritativenoyes / yesrefused2026.10.2
curt.ns.cloudflare.com 172.64.33.94NOERROR, 5 ms, authoritativenoyes / yesrefused2026.10.2
curt.ns.cloudflare.com 2606:4700:58::adf5:3b5eNOERROR, 6 ms, authoritativenoyes / yesrefused2026.10.2
curt.ns.cloudflare.com 2a06:98c1:50::ac40:215eNOERROR, 5 ms, authoritativenoyes / yesrefused2026.10.2
curt.ns.cloudflare.com 2803:f800:50::6ca2:c15eNOERROR, 8 ms, authoritativenoyes / yesrefused2026.10.2
joan.ns.cloudflare.com 173.245.58.173NOERROR, 6 ms, authoritativenoyes / yesrefused2026.10.2
joan.ns.cloudflare.com 172.64.32.173NOERROR, 6 ms, authoritativenoyes / yesrefused2026.10.2
joan.ns.cloudflare.com 108.162.192.173NOERROR, 8 ms, authoritativenoyes / yesrefused2026.10.2
joan.ns.cloudflare.com 2803:f800:50::6ca2:c0adNOERROR, 5 ms, authoritativenoyes / yesrefused2026.10.2
joan.ns.cloudflare.com 2a06:98c1:50::ac40:20adNOERROR, 5 ms, authoritativenoyes / yesrefused2026.10.2
joan.ns.cloudflare.com 2606:4700:50::adf5:3aadNOERROR, 5 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: curt.ns.cloudflare.com: "2026.10.2"; joan.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 2417745795 · primary curt.ns.cloudflare.com

Found

Primary (MNAME)
curt.ns.cloudflare.com
Contact (RNAME)
dns.cloudflare.com
Serial
2417745795
Refresh / retry
10000 s / 2400 s
Expire
604800 s
Negative TTL
1800 s

Serial per nameserver

NameserverSerial
curt.ns.cloudflare.com (108.162.193.94)2417745795
curt.ns.cloudflare.com (173.245.59.94)2417745795
curt.ns.cloudflare.com (172.64.33.94)2417745795
curt.ns.cloudflare.com (2606:4700:58::adf5:3b5e)2417745795
curt.ns.cloudflare.com (2a06:98c1:50::ac40:215e)2417745795
curt.ns.cloudflare.com (2803:f800:50::6ca2:c15e)2417745795
joan.ns.cloudflare.com (173.245.58.173)2417745795
joan.ns.cloudflare.com (172.64.32.173)2417745795
joan.ns.cloudflare.com (108.162.192.173)2417745795
joan.ns.cloudflare.com (2803:f800:50::6ca2:c0ad)2417745795
joan.ns.cloudflare.com (2a06:98c1:50::ac40:20ad)2417745795
joan.ns.cloudflare.com (2606:4700:50::adf5:3aad)2417745795

Checks

  • ✓ Serial 2417745795 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 curt.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 2417745795 is a Unix timestamp (2046-08-13 04:03 UTC).

DNSSEC

info

Signed, DS published at parent

Found

Validated by resolver
yes
Denial of existence
NSEC
Signatures valid until
23 October 2026

DS at the parent

Key tagAlgorithmDigestMatches a key
2371ECDSAP256SHA256 (13)SHA256 2D6011398CE9A0AA…yes

DNSKEY in the zone

Key tagRoleAlgorithm
2371KSK (257)ECDSAP256SHA256 (13)
34505ZSK (256)ECDSAP256SHA256 (13)

Checks

  • ✓ Signed and validated #27
    The zone is signed, the parent publishes a DS record, and the resolver validates the answers.
  • ✓ DS matches a key #28
    The DS record at the parent matches a key in the zone: key tag 2371 (SHA256).
  • ✓ Modern algorithms #29
    Key algorithms: ECDSAP256SHA256 (13).
  • ✓ Short-lived signatures (online signing) #30
    Signatures are valid for 50h0m0s and created on demand; the current one was made at 2026-10-21 09:25 UTC and expires at 2026-10-23 11:25 UTC.
  • i
    NSEC
    The zone uses NSEC, so its full contents can be listed by walking the NSEC chain. That is fine unless the names are sensitive.
    #31

Records

info

19 records at the apex

Found

Read from
108.162.193.94:53
TypeValueTTL
SOAcurt.ns.cloudflare.com. dns.cloudflare.com. 2417745795 10000 2400 604800 18001800
NScurt.ns.cloudflare.com.86400
NSjoan.ns.cloudflare.com.86400
A104.20.21.64300
A172.66.152.40300
AAAA2606:4700:10::6814:1540300
AAAA2606:4700:10::ac42:9828300
MX1 aspmx.l.google.com.300
MX10 alt3.aspmx.l.google.com.300
MX10 alt4.aspmx.l.google.com.300
MX5 alt1.aspmx.l.google.com.300
MX5 alt2.aspmx.l.google.com.300
TXT"ahrefs-site-verification_b23bde4d9aec7044956dcd71cf0d11f916b0e454decab322485d1711448974f4"300
TXT"facebook-domain-verification=mq46mq2is4d14vhplara08baid717h"300
TXT"google-site-verification=A7KGy9dXNDDjfcJxzeheQMV3zXmEaGyhfXGD8gVnV0o"300
TXT"google-site-verification=Ubborzk4tBqoxnQn8nPqAyMvR6MFiJEJABBL8_y63QQ"300
TXT"heroku-domain-verification=4wmxxfa6kei5mnhcv1uv9tupeqkktlelsdph/9h1zyw"300
TXT"openai-domain-verification=dv-fH5y7meWHKLGgcZuenhzq9WI"300
TXT"v=spf1 include:sendgrid.net include:_spf.google.com include:spf.mtasv.net -all"300

Checks

  • ✓ TTLs within range #32
    TTLs: A 5m, AAAA 5m, MX 5m, NS 1d. The NS TTL at the parent is 2d and in the zone 1d; 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