questia.com

Checked 22 October 2026, 10:24 UTC · via 8.8.8.8
!Passed with warnings
24 passed 2 warnings 0 failed 5 info

Registration

info

.com generic · Key-Systems GmbH · expires 2027-07-21

Found

TLD
.com (generic)
ICANN policies apply
yes
Registrar
Key-Systems GmbH
Registered
21 July 1999
Last changed
20 June 2026
Expires
21 July 2027
Status
client delete prohibited, client transfer prohibited
Registry nameservers
dns1.p01.nsone.net, dns2.p01.nsone.net, dns3.p01.nsone.net, dns4.p01.nsone.net
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 2027-07-21 #3
    The registration is valid until 2027-07-21 (272 days).
  • ✓ Transfer locked #4
    Registry status: client delete prohibited, client transfer prohibited.
  • ✓ Registry and delegation match #5
    The nameservers registered at the registry are the ones published in DNS.

Delegation

warn

dns1.p01.nsone.net, dns2.p01.nsone.net, dns3.p01.nsone.net, dns4.p01.nsone.net

Found

Parent zone
com
Delegation from
a.gtld-servers.net (192.5.6.30)
NS at the parent
dns1.p01.nsone.net, dns2.p01.nsone.net, dns3.p01.nsone.net, dns4.p01.nsone.net
NS in the zone
ns1x.cengage.net, ns2x.cengage.net
NameserverAddressesNetwork (AS)Glue
dns1.p01.nsone.net (parent only)198.51.44.1 2620:4d:4000:6259:7:1:0:1AS62597 NSONE - NSONE Inc, US AS62597 NSONE - NSONE Inc, US-
dns2.p01.nsone.net (parent only)198.51.45.1 2a00:edc0:6259:7:1::2AS62597 NSONE - NSONE Inc, US AS62597 NSONE - NSONE Inc, US-
dns3.p01.nsone.net (parent only)198.51.44.65 2620:4d:4000:6259:7:1:0:3AS62597 NSONE - NSONE Inc, US AS62597 NSONE - NSONE Inc, US-
dns4.p01.nsone.net (parent only)198.51.45.65 2a00:edc0:6259:7:1::4AS62597 NSONE - NSONE Inc, US AS62597 NSONE - NSONE Inc, US-
ns1x.cengage.net (zone only)69.32.130.251AS27365 CENGAGE-OHCIN - Cengage Learning, Inc., US-
ns2x.cengage.net (zone only)69.32.224.38AS27365 CENGAGE-OHCIN - Cengage Learning, Inc., US-

Checks

  • ✓ 4 nameservers #6
    Delegated to dns1.p01.nsone.net, dns2.p01.nsone.net, dns3.p01.nsone.net, dns4.p01.nsone.net.
  • !
    NS sets differ
    The nameservers at the parent and in the zone should be the same. Only at the parent: dns1.p01.nsone.net, dns2.p01.nsone.net, dns3.p01.nsone.net, dns4.p01.nsone.net; only in the zone: ns1x.cengage.net, ns2x.cengage.net. dns1.p01.nsone.net, dns2.p01.nsone.net, dns3.p01.nsone.net, dns4.p01.nsone.net, ns1x.cengage.net, ns2x.cengage.net report NS ns1x.cengage.net ns2x.cengage.net.
    #7
  • ✓ 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 4 IPv4 /24s and 2 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS27365 (CENGAGE-OHCIN - Cengage Learning, Inc., US): 2 addresses; AS62597 (NSONE - NSONE Inc, US): 8 addresses.
  • 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
  • i
    Partly IPv6
    These nameservers have no IPv6 address: ns1x.cengage.net, ns2x.cengage.net.
    #13

Nameservers

info

10 of 10 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns1.p01.nsone.net 198.51.44.1NOERROR, 11 ms, authoritativenoyes / yesrefused19dd46e347df36b70933bf2be8023258586586a9
dns1.p01.nsone.net 2620:4d:4000:6259:7:1:0:1NOERROR, 12 ms, authoritativenoyes / yesrefused19dd46e347df36b70933bf2be8023258586586a9
dns2.p01.nsone.net 198.51.45.1NOERROR, 4 ms, authoritativenoyes / yesrefused19dd46e347df36b70933bf2be8023258586586a9
dns2.p01.nsone.net 2a00:edc0:6259:7:1::2NOERROR, 4 ms, authoritativenoyes / yesrefused19dd46e347df36b70933bf2be8023258586586a9
dns3.p01.nsone.net 198.51.44.65NOERROR, 6 ms, authoritativenoyes / yesrefused19dd46e347df36b70933bf2be8023258586586a9
dns3.p01.nsone.net 2620:4d:4000:6259:7:1:0:3NOERROR, 4 ms, authoritativenoyes / yesrefused19dd46e347df36b70933bf2be8023258586586a9
dns4.p01.nsone.net 198.51.45.65NOERROR, 9 ms, authoritativenoyes / yesrefused19dd46e347df36b70933bf2be8023258586586a9
dns4.p01.nsone.net 2a00:edc0:6259:7:1::4NOERROR, 9 ms, authoritativenoyes / yesrefused19dd46e347df36b70933bf2be8023258586586a9
ns1x.cengage.net 69.32.130.251NOERROR, 110 ms, authoritativenoyes / yesrefused-
ns2x.cengage.net 69.32.224.38NOERROR, 110 ms, authoritativenoyes / yesrefused-

Checks

  • ✓ All respond #14
    All 10 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: dns1.p01.nsone.net: "19dd46e347df36b70933bf2be8023258586586a9"; dns2.p01.nsone.net: "19dd46e347df36b70933bf2be8023258586586a9"; dns3.p01.nsone.net: "19dd46e347df36b70933bf2be8023258586586a9"; dns4.p01.nsone.net: "19dd46e347df36b70933bf2be8023258586586a9".
    #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 2012122612 · primary ns1x.cengage.net

Found

Primary (MNAME)
ns1x.cengage.net
Contact (RNAME)
hostmaster.ohcinmason.com
Serial
2012122612
Refresh / retry
3600 s / 1800 s
Expire
1036800 s
Negative TTL
900 s

Serial per nameserver

NameserverSerial
dns1.p01.nsone.net (198.51.44.1)2012122612
dns1.p01.nsone.net (2620:4d:4000:6259:7:1:0:1)2012122612
dns2.p01.nsone.net (198.51.45.1)2012122612
dns2.p01.nsone.net (2a00:edc0:6259:7:1::2)2012122612
dns3.p01.nsone.net (198.51.44.65)2012122612
dns3.p01.nsone.net (2620:4d:4000:6259:7:1:0:3)2012122612
dns4.p01.nsone.net (198.51.45.65)2012122612
dns4.p01.nsone.net (2a00:edc0:6259:7:1::4)2012122612
ns1x.cengage.net (69.32.130.251)2012122612
ns2x.cengage.net (69.32.224.38)2012122612

Checks

  • ✓ Serial 2012122612 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 1h, retry 30m, expire 12d, negative TTL 15m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns1x.cengage.net is one of the listed nameservers.
  • ✓ Contact hostmaster@ohcinmason.com #25
    The SOA RNAME hostmaster.ohcinmason.com means hostmaster@ohcinmason.com.
  • ✓ Date-based serial #26
    The serial 2012122612 follows the YYYYMMDDnn convention (2012-12-26).

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

8 records at the apex

Found

Read from
198.51.44.1:53
TypeValueTTL
SOAns1x.cengage.net. hostmaster.ohcinmason.com. 2012122612 3600 1800 1036800 900300
NSns1x.cengage.net.300
NSns2x.cengage.net.300
A69.32.208.15300
MX10 mxa-0012df01.gslb.pphosted.com.300
MX10 mxb-0012df01.gslb.pphosted.com.300
TXT"MS=ms21994581"300
TXT"v=spf1 include:spf.cengage.com -all"300

Checks

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