slb.com

Checked 22 October 2026, 10:44 UTC · via 8.8.8.8
!Passed with warnings
26 passed 2 warnings 0 failed 3 info

Registration

info

.com generic · Tucows Domains Inc. · expires 2027-05-21

Found

TLD
.com (generic)
ICANN policies apply
yes
Registrar
Tucows Domains Inc.
Registered
20 May 1987
Last changed
22 April 2026
Expires
21 May 2027
Status
client transfer prohibited, client update prohibited
Registry nameservers
dns0.slb.com, dns0.slb.net, dns1.slb.com, dns1.slb.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 2027-05-21 #3
    The registration is valid until 2027-05-21 (210 days).
  • ✓ Transfer locked #4
    Registry status: client transfer prohibited, client update prohibited.
  • ✓ Registry and delegation match #5
    The nameservers registered at the registry are the ones published in DNS.

Delegation

warn

dns0.slb.com, dns0.slb.net, dns1.slb.com, dns1.slb.net

Found

Parent zone
com
Delegation from
a.gtld-servers.net (192.5.6.30)
NS at the parent
dns0.slb.com, dns0.slb.net, dns1.slb.com, dns1.slb.net
NS in the zone
dns0.slb.com, dns0.slb.net, dns1.slb.com, dns1.slb.net, ns74.ultradns2.com, ns74.ultradns2.org
NameserverAddressesNetwork (AS)Glue
dns0.slb.com156.154.64.109 2001:502:f3ff::91AS12008 VERCARA - Vercara, LLC, US AS12008 VERCARA - Vercara, LLC, US156.154.64.109 2001:502:f3ff::91
dns0.slb.net156.154.66.109 2610:a1:1015::91AS12008 VERCARA - Vercara, LLC, US AS12008 VERCARA - Vercara, LLC, US-
dns1.slb.com156.154.65.109 2610:a1:1014::91AS12008 VERCARA - Vercara, LLC, US AS12008 VERCARA - Vercara, LLC, US156.154.65.109 2610:a1:1014::91
dns1.slb.net156.154.67.109 2001:502:4612::91AS12008 VERCARA - Vercara, LLC, US AS12008 VERCARA - Vercara, LLC, US-
ns74.ultradns2.com (zone only)204.74.104.74 2610:a1:314a::53AS399153 SECURITYSERVICES - Vercara, LLC, US AS399155 SECURITYSERVICES - Vercara, LLC, US-
ns74.ultradns2.org (zone only)204.74.106.74 2610:a1:324a::53AS399154 SECURITYSERVICES - Vercara, LLC, US AS399154 SECURITYSERVICES - Vercara, LLC, US-

Checks

  • ✓ 4 nameservers #6
    Delegated to dns0.slb.com, dns0.slb.net, dns1.slb.com, dns1.slb.net.
  • !
    NS sets differ
    The nameservers at the parent and in the zone should be the same. Only in the zone: ns74.ultradns2.com, ns74.ultradns2.org. dns0.slb.com, dns0.slb.net, dns1.slb.com, dns1.slb.net, ns74.ultradns2.com, ns74.ultradns2.org report NS dns0.slb.com dns0.slb.net dns1.slb.com dns1.slb.net ns74.ultradns2.com ns74.ultradns2.org.
    #7
  • ✓ Glue present and correct #8
    Glue is published for the nameservers inside the zone: dns0.slb.com, dns1.slb.com.
  • ✓ 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 6 IPv6 /48s.
  • ✓ 4 autonomous systems #11
    The nameservers are spread over: AS12008 (VERCARA - Vercara, LLC, US): 8 addresses; AS399153 (SECURITYSERVICES - Vercara, LLC, US): 1 address; AS399154 (SECURITYSERVICES - Vercara, LLC, US): 2 addresses; AS399155 (SECURITYSERVICES - Vercara, LLC, US): 1 address.
  • ✓ Nameserver names under 2 TLDs #12
    Nameserver names use the TLDs .com, .net.
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

info

12 of 12 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns0.slb.com 156.154.64.109NOERROR, 3 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
dns0.slb.com 2001:502:f3ff::91NOERROR, 4 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
dns0.slb.net 156.154.66.109NOERROR, 4 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
dns0.slb.net 2610:a1:1015::91NOERROR, 4 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
dns1.slb.com 156.154.65.109NOERROR, 4 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
dns1.slb.com 2610:a1:1014::91NOERROR, 4 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
dns1.slb.net 156.154.67.109NOERROR, 31 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
dns1.slb.net 2001:502:4612::91NOERROR, 32 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
ns74.ultradns2.com 204.74.104.74NOERROR, 4 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
ns74.ultradns2.com 2610:a1:314a::53NOERROR, 4 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
ns74.ultradns2.org 204.74.106.74NOERROR, 9 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
ns74.ultradns2.org 2610:a1:324a::53NOERROR, 10 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver

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.
  • i
    Identifying string disclosed
    These nameservers answer version queries with a string that is not a version number: dns0.slb.com: "UltraDNS Nameserver"; dns0.slb.net: "UltraDNS Nameserver"; dns1.slb.com: "UltraDNS Nameserver"; dns1.slb.net: "UltraDNS Nameserver"; ns74.ultradns2.com: "UltraDNS Nameserver"; ns74.ultradns2.org: "UltraDNS Nameserver".
    #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 7441 · primary dns0.slb.com

Found

Primary (MNAME)
dns0.slb.com
Contact (RNAME)
hostmaster.slb.com
Serial
7441
Refresh / retry
14400 s / 3600 s
Expire
2419200 s
Negative TTL
2400 s

Serial per nameserver

NameserverSerial
dns0.slb.com (156.154.64.109)7441
dns0.slb.com (2001:502:f3ff::91)7441
dns0.slb.net (156.154.66.109)7441
dns0.slb.net (2610:a1:1015::91)7441
dns1.slb.com (156.154.65.109)7441
dns1.slb.com (2610:a1:1014::91)7441
dns1.slb.net (156.154.67.109)7441
dns1.slb.net (2001:502:4612::91)7441
ns74.ultradns2.com (204.74.104.74)7441
ns74.ultradns2.com (2610:a1:314a::53)7441
ns74.ultradns2.org (204.74.106.74)7441
ns74.ultradns2.org (2610:a1:324a::53)7441

Checks

  • ✓ Serial 7441 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 4h, retry 1h, expire 28d, negative TTL 40m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver dns0.slb.com is one of the listed nameservers.
  • ✓ Contact hostmaster@slb.com #25
    The SOA RNAME hostmaster.slb.com means hostmaster@slb.com.
  • ✓ Counter serial #26
    The serial 7441 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
156.154.64.109:53
TypeValueTTL
SOAdns0.slb.com. hostmaster.slb.com. 7441 14400 3600 2419200 240086400
NSdns0.slb.com.86400
NSdns0.slb.net.86400
NSdns1.slb.com.86400
NSdns1.slb.net.86400
NSns74.ultradns2.com.86400
NSns74.ultradns2.org.86400
A20.23.79.56300
MX100 mxa-00198502.gslb.pphosted.com.86400
MX100 mxb-00198502.gslb.pphosted.com.86400
TXT"Token" "_f9z007il9fng3a9sccr1dj5goaqpc7v"86400
TXT"MS=ms89274394"86400
TXT"v=spf1 include:spf.slb.com -all"86400
TXT"_6oavsfza0onvgs01fh9f3r3so8ypauq"86400
TXT"_fmf0j3qau9k6dmjnq8tt1jsr0wlhcp8"86400
TXT"_hbc7vup0me2zg11dcjn680lkchv44vh"86400
TXT"_y7w4e8nfjef7knlhh2lapiza34j7ibx"86400
TXT"apple-domain-verification=SHe3xQCdfNnfOpTI"86400
TXT"flexera-domain-verification-lxfioswenyubkztt"86400
TXT"status-page-domain-verification=v3hz8n0w7g3s"86400
TXT"docusign=085ff53d-356a-4390-9af9-a922f5f8b093"86400
TXT"docusign=16608844-f3ec-4806-a10b-222f4820b9ec"86400
TXT"amazonses:35pO+s+qcEXAdefgrB7FVzLEpcchpPOMQN8fgzD0PfY="86400
TXT"amazonses:B9ZjxebgwwOtCAUisMo4ei6KCMN2ABvqEq0nSdx1+eA="86400
TXT"amazonses:v0Sw1pQnTWdKqr2pZo1cZ1bxcjsvnRt1GbIo4qU/wAQ="86400
TXT"Foxit-domain-verification=90b03bccea900ccf3be052b1136ebf2d"86400
TXT"famac-domain-verification=Apwtz1uvjM5ZpZzyzehRwqvmuleDaMC5"86400
TXT"dtm-domain-verification=qG82-AK3uGtwlQf_qwwPrkEwabGkn0rlVsjJYeYEKgg"86400
TXT"google-site-verification=D9h69BPYFFi9QCt0SKXsWCufED_oXmfVlmRap5B7UMs"86400
TXT"google-site-verification=XtFCPxMCEBsoUeOexOW9Kk5hulo80aV9i-4pS8_oveU"86400
TXT"google-site-verification=muu7Yen_EnoV3Id-XnT0EhJuopYSkI-Cry66cBjWIWw"86400
TXT"insomnia-validation=8689320df65f49e88094f4e79073d00ad285ea60f15b53f691881b0ce0cdc7d8"86400
TXT"3E9IyQshdOGeZOwXbophEs4zy+nE8MSx/dbBbCEXsYCbNH7fqhpA0PntyYXpFSYVX/Xj0blvagUKKY+RESTM0A=="86400
TXT"M+6z/U3Gc9+5MdRQC+LZODM+EpUOgzxbqA4i+urC1a34r9VG8ZvN7MtVi+/gEUcZSD5zBiB/8+6bSm9ch4MDdQ=="86400
TXT"hcp-domain-verification=f59a5b308fc66a41668ec1259a8f3067b39195ba77d4c053edf571cbc720d0d8"86400
TXT"atlassian-domain-verification=7aloX7uS/PUrSxEXq/KDqMTCnrKDhcUEEB4qVfOKY0SQanEc9XzSjbd2QwwIfFy5"86400
TXT"atlassian-domain-verification=Hm8nqYyuAAYIPtQv9h7XRGFaN9byHoIYST7wS586VV8fIfSHpf78uHLCbn14nT3d"86400
TXT"postman-domain-verification=f670cc40b987f018975e55a0a5522458d390d8ae31fdb0b647a49d2db720454de374f1478f3edf2e7895917151412e6175fdedbbcf14fb48c6e74fcab8682acf"86400
CAA0 iodef "mailto:pki-admin-manager@slb.com"900
CAA0 issue "amazon.com"900
CAA0 issue "digicert.com"900
CAA0 issuewild "digicert.com"900

Checks

  • ✓ TTLs within range #32
    TTLs: A 5m, MX 1d, 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.
  • i
    Wildcard record
    A random name under the zone resolves, so there is a wildcard (*) record. Typos and non-existent hosts resolve too, which can confuse mail and certificate checks.
    #34
  • ✓ CAA restricts issuance #35
    Certificates may be issued by: amazon.com, digicert.com.