submarinecablemap.com

Checked 22 October 2026, 10:52 UTC · via 8.8.8.8
!Passed with warnings
24 passed 3 warnings 0 failed 4 info

Registration

info

.com generic · CSL Computer Service Langenbach GmbH d/b/a joker.com · expires 2028-09-01

Found

TLD
.com (generic)
ICANN policies apply
yes
Registrar
CSL Computer Service Langenbach GmbH d/b/a joker.com
Registered
1 September 2011
Last changed
3 August 2025
Expires
1 September 2028
Status
client transfer prohibited
Registry nameservers
ns1.digitalocean.com, ns2.digitalocean.com, ns3.digitalocean.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 2028-09-01 #3
    The registration is valid until 2028-09-01 (680 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

warn

ns1.digitalocean.com, ns2.digitalocean.com, ns3.digitalocean.com

Found

Parent zone
com
Delegation from
a.gtld-servers.net (192.5.6.30)
NS at the parent
ns1.digitalocean.com, ns2.digitalocean.com, ns3.digitalocean.com
NS in the zone
ns1.digitalocean.com, ns2.digitalocean.com, ns3.digitalocean.com
NameserverAddressesNetwork (AS)Glue
ns1.digitalocean.com172.64.52.210 2606:4700:52::ac40:34d2AS13335 CLOUDFLARENET - Cloudflare, Inc., US AS13335 CLOUDFLARENET - Cloudflare, Inc., US172.64.52.210
ns2.digitalocean.com172.64.53.21 2606:4700:5a::ac40:3515AS13335 CLOUDFLARENET - Cloudflare, Inc., US AS13335 CLOUDFLARENET - Cloudflare, Inc., US172.64.53.21
ns3.digitalocean.com172.64.49.209 2606:4700:52::ac40:31d1AS13335 CLOUDFLARENET - Cloudflare, Inc., US AS13335 CLOUDFLARENET - Cloudflare, Inc., US172.64.49.209

Checks

  • ✓ 3 nameservers #6
    Delegated to ns1.digitalocean.com, ns2.digitalocean.com, ns3.digitalocean.com.
  • ✓ Parent and zone agree #7
    The parent delegation and the zone's NS records list the same nameservers.
  • !
    Glue differs from the zone
    The addresses at the parent (glue) differ from the addresses in the zone: ns1.digitalocean.com (glue 172.64.52.210, zone 172.64.52.210, 2606:4700:52::ac40:34d2); ns2.digitalocean.com (glue 172.64.53.21, zone 172.64.53.21, 2606:4700:5a::ac40:3515); ns3.digitalocean.com (glue 172.64.49.209, zone 172.64.49.209, 2606:4700:52::ac40:31d1). Update the glue at your registrar.
    #8
  • ✓ 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 2 IPv6 /48s.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS13335 (CLOUDFLARENET - Cloudflare, Inc., US): 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 .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

6 of 6 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns1.digitalocean.com 172.64.52.210NOERROR, 64 ms, authoritativenoyes / yesrefused2026.10.8
ns1.digitalocean.com 2606:4700:52::ac40:34d2NOERROR, 64 ms, authoritativenoyes / yesrefused2026.10.8
ns2.digitalocean.com 172.64.53.21NOERROR, 66 ms, authoritativenoyes / yesrefused2026.10.8
ns2.digitalocean.com 2606:4700:5a::ac40:3515NOERROR, 65 ms, authoritativenoyes / yesrefused2026.10.8
ns3.digitalocean.com 172.64.49.209NOERROR, 10 ms, authoritativenoyes / yesrefused2026.10.8
ns3.digitalocean.com 2606:4700:52::ac40:31d1NOERROR, 67 ms, authoritativenoyes / yesrefused2026.10.8

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.
  • !
    Software version disclosed
    These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: ns1.digitalocean.com: "2026.10.8"; ns2.digitalocean.com: "2026.10.8"; ns3.digitalocean.com: "2026.10.8". 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 0 · primary ns1.digitalocean.com

Found

Primary (MNAME)
ns1.digitalocean.com
Contact (RNAME)
hostmaster.submarinecablemap.com
Serial
0
Refresh / retry
10800 s / 3600 s
Expire
604800 s
Negative TTL
1800 s

Serial per nameserver

NameserverSerial
ns1.digitalocean.com (172.64.52.210)0
ns1.digitalocean.com (2606:4700:52::ac40:34d2)0
ns2.digitalocean.com (172.64.53.21)0
ns2.digitalocean.com (2606:4700:5a::ac40:3515)0
ns3.digitalocean.com (172.64.49.209)0
ns3.digitalocean.com (2606:4700:52::ac40:31d1)0

Checks

  • ✓ Serial 0 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 3h, retry 1h, expire 7d, negative TTL 30m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns1.digitalocean.com is one of the listed nameservers.
  • ✓ Contact hostmaster@submarinecablemap.com #25
    The SOA RNAME hostmaster.submarinecablemap.com means hostmaster@submarinecablemap.com.
  • ✓ Counter serial #26
    The serial 0 is a plain counter.

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

5 records at the apex

Found

Read from
172.64.52.210:53
TypeValueTTL
SOAns1.digitalocean.com. hostmaster.submarinecablemap.com. 0 10800 3600 604800 18001800
NSns1.digitalocean.com.1800
NSns3.digitalocean.com.1800
NSns2.digitalocean.com.1800
A54.162.122.240300

Checks

  • ✓ TTLs within range #32
    TTLs: A 5m, NS 30m. The NS TTL at the parent is 2d and in the zone 30m; 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