si.com

Checked 22 October 2026, 10:42 UTC · via 8.8.8.8
!Passed with warnings
27 passed 1 warning 0 failed 3 info

Registration

info

.com generic · MarkMonitor Inc. · expires 2027-07-05

Found

TLD
.com (generic)
ICANN policies apply
yes
Registrar
MarkMonitor Inc.
Registered
6 July 1990
Last changed
3 June 2025
Expires
5 July 2027
Status
client delete prohibited, client transfer prohibited, client update prohibited
Registry nameservers
ns-1157.awsdns-16.org, ns-1819.awsdns-35.co.uk, ns-474.awsdns-59.com, ns-741.awsdns-28.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 2027-07-05 #3
    The registration is valid until 2027-07-05 (255 days).
  • ✓ Transfer locked #4
    Registry status: client delete prohibited, client transfer prohibited, client update prohibited.
  • ✓ Registry and delegation match #5
    The nameservers registered at the registry are the ones published in DNS.

Delegation

info

ns-1157.awsdns-16.org, ns-1819.awsdns-35.co.uk, ns-474.awsdns-59.com, ns-741.awsdns-28.net

Found

Parent zone
com
Delegation from
a.gtld-servers.net (192.5.6.30)
NS at the parent
ns-1157.awsdns-16.org, ns-1819.awsdns-35.co.uk, ns-474.awsdns-59.com, ns-741.awsdns-28.net
NS in the zone
ns-1157.awsdns-16.org, ns-1819.awsdns-35.co.uk, ns-474.awsdns-59.com, ns-741.awsdns-28.net
NameserverAddressesNetwork (AS)Glue
ns-1157.awsdns-16.org205.251.196.133 2600:9000:5304:8500::1AS16509 AMAZON-02 - Amazon.com, Inc., US AS16509 AMAZON-02 - Amazon.com, Inc., US-
ns-1819.awsdns-35.co.uk205.251.199.27 2600:9000:5307:1b00::1AS16509 AMAZON-02 - Amazon.com, Inc., US AS16509 AMAZON-02 - Amazon.com, Inc., US-
ns-474.awsdns-59.com205.251.193.218 2600:9000:5301:da00::1AS16509 AMAZON-02 - Amazon.com, Inc., US AS16509 AMAZON-02 - Amazon.com, Inc., US205.251.193.218 2600:9000:5301:da00::1
ns-741.awsdns-28.net205.251.194.229 2600:9000:5302:e500::1AS16509 AMAZON-02 - Amazon.com, Inc., US AS16509 AMAZON-02 - Amazon.com, Inc., US-

Checks

  • ✓ 4 nameservers #6
    Delegated to ns-1157.awsdns-16.org, ns-1819.awsdns-35.co.uk, ns-474.awsdns-59.com, ns-741.awsdns-28.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 4 IPv4 /24s and 4 IPv6 /48s.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS16509 (AMAZON-02 - Amazon.com, Inc., US): 8 addresses). An outage or attack on that network affects all nameservers; large anycast providers mitigate this, but a secondary DNS provider adds independence.
    #11
  • ✓ Nameserver names under 4 TLDs #12
    Nameserver names use the TLDs .com, .net, .org, .uk.
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

pass

8 of 8 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns-1157.awsdns-16.org 205.251.196.133NOERROR, 3 ms, authoritativenoyes / yesrefused-
ns-1157.awsdns-16.org 2600:9000:5304:8500::1NOERROR, 4 ms, authoritativenoyes / yesrefused-
ns-1819.awsdns-35.co.uk 205.251.199.27NOERROR, 9 ms, authoritativenoyes / yesrefused-
ns-1819.awsdns-35.co.uk 2600:9000:5307:1b00::1NOERROR, 9 ms, authoritativenoyes / yesrefused-
ns-474.awsdns-59.com 205.251.193.218NOERROR, 9 ms, authoritativenoyes / yesrefused-
ns-474.awsdns-59.com 2600:9000:5301:da00::1NOERROR, 9 ms, authoritativenoyes / yesrefused-
ns-741.awsdns-28.net 205.251.194.229NOERROR, 4 ms, authoritativenoyes / yesrefused-
ns-741.awsdns-28.net 2600:9000:5302:e500::1NOERROR, 5 ms, authoritativenoyes / yesrefused-

Checks

  • ✓ All respond #14
    All 8 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.
  • ✓ No version disclosed #17
    The nameservers don't reveal their software version.
  • ✓ 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 1 · primary ns-1819.awsdns-35.co.uk

Found

Primary (MNAME)
ns-1819.awsdns-35.co.uk
Contact (RNAME)
awsdns-hostmaster.amazon.com
Serial
1
Refresh / retry
7200 s / 900 s
Expire
1209600 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
ns-1157.awsdns-16.org (205.251.196.133)1
ns-1157.awsdns-16.org (2600:9000:5304:8500::1)1
ns-1819.awsdns-35.co.uk (205.251.199.27)1
ns-1819.awsdns-35.co.uk (2600:9000:5307:1b00::1)1
ns-474.awsdns-59.com (205.251.193.218)1
ns-474.awsdns-59.com (2600:9000:5301:da00::1)1
ns-741.awsdns-28.net (205.251.194.229)1
ns-741.awsdns-28.net (2600:9000:5302:e500::1)1

Checks

  • ✓ Serial 1 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 2h, retry 15m, expire 14d, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns-1819.awsdns-35.co.uk is one of the listed nameservers.
  • ✓ Contact awsdns-hostmaster@amazon.com #25
    The SOA RNAME awsdns-hostmaster.amazon.com means awsdns-hostmaster@amazon.com.
  • ✓ Counter serial #26
    The serial 1 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

42 records at the apex

Found

Read from
205.251.196.133:53
TypeValueTTL
SOAns-1819.awsdns-35.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400900
NSns-1157.awsdns-16.org.172800
NSns-1819.awsdns-35.co.uk.172800
NSns-474.awsdns-59.com.172800
NSns-741.awsdns-28.net.172800
A35.83.190.2253600
A44.241.188.243600
MX1 aspmx.l.google.com.3600
MX10 alt3.aspmx.l.google.com.3600
MX10 alt4.aspmx.l.google.com.3600
MX5 alt1.aspmx.l.google.com.3600
MX5 alt2.aspmx.l.google.com.3600
TXT"26C1DCCA46"600
TXT"MS=ms22369655"600
TXT"MS=ms80782080"600
TXT"MS=ms93495782"600
TXT"T0I0M34279"600
TXT"_globalsign-domain-verification=m2caqrJ1kIVyqQ3xPGWo5qP93lYtTkKA0Xyz-eQIA-"600
TXT"airtable-verification=cc7c4ecba9339dd98d28575a1f939dc6"600
TXT"anthropic-domain-verification-fxa68d=36o8GgBUJXPVkmkYQi85g7YTC"600
TXT"apple-domain-verification=rGtFLx1dBQPK35RZ"600
TXT"atlassian-domain-verification=49CoabLOiRcDOq7aYk5YiRo9mbmOMsuyotiNaBC0Z7Id5yRBgwYVT8WucbUy6t4n"600
TXT"d3bmdi80xb3jem.cloudfront.net"600
TXT"docusign=1037b789-2196-4c77-809c-66b8c6836a02"600
TXT"docusign=550d3e50-7b29-4e9b-8edb-272c801fb362"600
TXT"facebook-domain-verification=yyyv3w5rx5pkpu6j4b5mvsqmknfwck"600
TXT"google-gws-recovery-domain-verification=50323461"600
TXT"google-site-verification=BcL9B2Akn-yQKEoovOAd83GCUTtWsMyfxgEI1-0sG8g"600
TXT"google-site-verification=ErcFNmd8Bdyx9ndPqktnlCh6aJifFW3Az2Ke4fq3oJ8"600
TXT"google-site-verification=JM0HYeXMzwZJ1PpC42J2vgYeE-NR_zreDuTMeJmNtPA"600
TXT"google-site-verification=K71xxdZMmsclZj94rwAHN4-KqN7-71w4TCxWjEpIDOI"600
TXT"google-site-verification=NXI0vQYm-vJsY1tnINxz2Q9dYSVlNUTfOW1R1igowpE"600
TXT"google-site-verification=WlbkowvStwyJiUSuqTdyEA7-DFv5aEdzBZAJX2lIHHc"600
TXT"google-site-verification=bUpqwbXU00vHWLNGYM-SzjHLYHFpZISN0nd8a_iaql8"600
TXT"google-site-verification=plyb-kJaEvatag0omktSRttmhBXb5evQhfH6tSkd6Yk"600
TXT"have-i-been-pwned-verification=517958ff82c3dcfa6b56d3c48af22b50"600
TXT"knowbe4-site-verification=6e8bc2272a23f6b229a16d1d421f11af"600
TXT"lAipka1cQ8WGr8k1FL9n7R4EV5UM2nrExypMNU7Squm/OkzjwHKtd7BRjv1gMOjcHt0l9IIEhu0vYfQbA6Qu1Q=="600
TXT"openai-domain-verification=dv-UBEyjIcV7fUyu6L23fw2HGci"600
TXT"v=spf1 include:aspmx.sailthru.com include:_spf.google.com include:amazonses.com ~all"600
TXT"yahoo-verification-key=3WCMllI0l93vs//RVwfdUD+IJ5X32ca7hi50mYH+7yg="600
TXT"yahoo-verification-key=VQrrIOsxWaqgo1rt85rk6qCXy5OHiXXdAONFzJYIHW0="600

Checks

  • ✓ TTLs within range #32
    TTLs: A 1h, MX 1h, NS 2d.
  • ✓ 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