twitter.com

Checked 22 October 2026, 11:14 UTC · via 8.8.8.8
!Passed with warnings
24 passed 3 warnings 0 failed 4 info

Registration

info

.com generic · CSC Corporate Domains, Inc. · expires 2027-01-21

Found

TLD
.com (generic)
ICANN policies apply
yes
Registrar
CSC Corporate Domains, Inc.
Registered
21 January 2000
Last changed
17 January 2026
Expires
21 January 2027
Status
client transfer prohibited, server delete prohibited, server transfer prohibited, server update prohibited
Registry nameservers
a.r06.twtrdns.net, a.u06.twtrdns.net, b.r06.twtrdns.net, b.u06.twtrdns.net, c.r06.twtrdns.net, c.u06.twtrdns.net, d.r06.twtrdns.net, d.u06.twtrdns.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 2027-01-21 #3
    The registration is valid until 2027-01-21 (91 days).
  • ✓ Transfer locked #4
    Registry status: client transfer prohibited, server delete prohibited, server transfer prohibited, server update prohibited.
  • ✓ Registry and delegation match #5
    The nameservers registered at the registry are the ones published in DNS.

Delegation

warn

a.r06.twtrdns.net, a.u06.twtrdns.net, b.r06.twtrdns.net, b.u06.twtrdns.net, c.r06.twtrdns.net, c.u06.twtrdns.net, d.r06.twtrdns.net, d.u06.twtrdns.net

Found

Parent zone
com
Delegation from
a.gtld-servers.net (192.5.6.30)
NS at the parent
a.r06.twtrdns.net, a.u06.twtrdns.net, b.r06.twtrdns.net, b.u06.twtrdns.net, c.r06.twtrdns.net, c.u06.twtrdns.net, d.r06.twtrdns.net, d.u06.twtrdns.net
NS in the zone
a.r06.twtrdns.net, a.u06.twtrdns.net, b.r06.twtrdns.net, b.u06.twtrdns.net, c.r06.twtrdns.net, c.u06.twtrdns.net, d.r06.twtrdns.net, d.u06.twtrdns.net
NameserverAddressesNetwork (AS)Glue
a.r06.twtrdns.net205.251.192.179AS16509 AMAZON-02 - Amazon.com, Inc., US-
a.u06.twtrdns.net204.74.111.101AS12008 VERCARA - Vercara, LLC, US-
b.r06.twtrdns.net205.251.196.198AS16509 AMAZON-02 - Amazon.com, Inc., US-
b.u06.twtrdns.net205.251.196.198AS16509 AMAZON-02 - Amazon.com, Inc., US-
c.r06.twtrdns.net205.251.194.151AS16509 AMAZON-02 - Amazon.com, Inc., US-
c.u06.twtrdns.net205.251.194.151AS16509 AMAZON-02 - Amazon.com, Inc., US-
d.r06.twtrdns.net205.251.199.195AS16509 AMAZON-02 - Amazon.com, Inc., US-
d.u06.twtrdns.net205.251.199.195AS16509 AMAZON-02 - Amazon.com, Inc., US-

Checks

  • ✓ 8 nameservers #6
    Delegated to a.r06.twtrdns.net, a.u06.twtrdns.net, b.r06.twtrdns.net, b.u06.twtrdns.net, c.r06.twtrdns.net, c.u06.twtrdns.net, d.r06.twtrdns.net, d.u06.twtrdns.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 5 IPv4 /24s and 0 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS12008 (VERCARA - Vercara, LLC, US): 1 address; AS16509 (AMAZON-02 - Amazon.com, Inc., US): 7 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
  • !
    No IPv6
    None of the nameservers has an IPv6 address, so IPv6-only resolvers can't reach them.
    #13

Nameservers

info

8 of 8 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
a.r06.twtrdns.net 205.251.192.179NOERROR, 9 ms, authoritativenoyes / yesrefused-
a.u06.twtrdns.net 204.74.111.101NOERROR, 13 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
b.r06.twtrdns.net 205.251.196.198NOERROR, 3 ms, authoritativenoyes / yesrefused-
b.u06.twtrdns.net 205.251.196.198NOERROR, 3 ms, authoritativenoyes / yesrefused-
c.r06.twtrdns.net 205.251.194.151NOERROR, 3 ms, authoritativenoyes / yesrefused-
c.u06.twtrdns.net 205.251.194.151NOERROR, 4 ms, authoritativenoyes / yesrefused-
d.r06.twtrdns.net 205.251.199.195NOERROR, 9 ms, authoritativenoyes / yesrefused-
d.u06.twtrdns.net 205.251.199.195NOERROR, 9 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.
  • i
    Identifying string disclosed
    These nameservers answer version queries with a string that is not a version number: a.u06.twtrdns.net: "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

warn

serial 2024011501 · primary a.u06.twtrdns.net

Found

Primary (MNAME)
a.u06.twtrdns.net
Contact (RNAME)
noc.twitter.com
Serial
2024011501
Refresh / retry
3600 s / 600 s
Expire
604800 s
Negative TTL
7200 s

Serial per nameserver

NameserverSerial
a.r06.twtrdns.net (205.251.192.179)2024011501
a.u06.twtrdns.net (204.74.111.101)2024169648
b.r06.twtrdns.net (205.251.196.198)2024011501
b.u06.twtrdns.net (205.251.196.198)2024011501
c.r06.twtrdns.net (205.251.194.151)2024011501
c.u06.twtrdns.net (205.251.194.151)2024011501
d.r06.twtrdns.net (205.251.199.195)2024011501
d.u06.twtrdns.net (205.251.199.195)2024011501

Checks

  • !
    Serials differ
    The nameservers serve different versions of the zone: 2024011501 on a.r06.twtrdns.net (205.251.192.179), b.r06.twtrdns.net (205.251.196.198), b.u06.twtrdns.net (205.251.196.198), c.r06.twtrdns.net (205.251.194.151), c.u06.twtrdns.net (205.251.194.151), d.r06.twtrdns.net (205.251.199.195), d.u06.twtrdns.net (205.251.199.195); 2024169648 on a.u06.twtrdns.net (204.74.111.101). This is normal for a few minutes after a change; if it lasts, zone transfers to the secondaries are failing.
    #22
  • ✓ Timers within recommendations #23
    SOA refresh 1h, retry 10m, expire 7d, negative TTL 2h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver a.u06.twtrdns.net is one of the listed nameservers.
  • ✓ Contact noc@twitter.com #25
    The SOA RNAME noc.twitter.com means noc@twitter.com.
  • ✓ Date-based serial #26
    The serial 2024011501 follows the YYYYMMDDnn convention (2024-01-15).

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

39 records at the apex

Found

Read from
205.251.192.179:53
TypeValueTTL
SOAa.u06.twtrdns.net. noc.twitter.com. 2024011501 3600 600 604800 72007200
NSa.r06.twtrdns.net.13999
NSa.u06.twtrdns.net.13999
NSb.r06.twtrdns.net.13999
NSb.u06.twtrdns.net.13999
NSc.r06.twtrdns.net.13999
NSc.u06.twtrdns.net.13999
NSd.r06.twtrdns.net.13999
NSd.u06.twtrdns.net.13999
A172.66.0.227300
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"0a8c0fc6-bfa5-4ea7-b09b-87f2989022d6"293
TXT"MS=BEE202D20C326867290BDEFA2DDDF4594B5D6860"293
TXT"adobe-idp-site-verification=a2ff8fc40c434d1d6f02f68b0b1a683e400572ab8c1f2c180c71c3d985b9270a"293
TXT"apple-domain-verification=zd1iHoEO9LILEQIq"293
TXT"atlassian-domain-verification=j6u0o1PTkobCXC84uEF/sWpIPtaZURBVYqKzmTvT8wugLcHT1vvrzzA63iP1qSLN"293
TXT"bj6sbt5xqs9hw9jrfvz7hplrg0l680sb"293
TXT"canva-site-verification=lMnZ3wMh7c1uqZqa-cxZTg"293
TXT"google-site-verification=600dQ0pZYsH2xOFt4hYmf5f5NpjCbWE_qk5Y04dErYM"293
TXT"google-site-verification=F2uUiLUsD6kQlpUVQzxUM3PHa0uPo5GBS84SCG8QwXI"293
TXT"google-site-verification=P9-NRZ0gaRKRGNDOXOjct5XETPtr3P9D-XA8HnlbAy4"293
TXT"google-site-verification=TNhAkfLUeIbzzzSgPNxS5aEkKMf3aUcpPmCK1_kmIvU"293
TXT"google-site-verification=h6dJIv0HXjLOkGAotLAWEzvoi9SxqP4vjpx98vrCvvQ"293
TXT"google-site-verification=q1ghWjGLX9Ba-Gy_B4n_pAgC_mQYzWmQpOD8CMWl_Hw"293
TXT"linear-domain-verification=t5iq7e7nbw5w"293
TXT"loom-site-verification=638c6bc173b9458997f64d305bf42499"293
TXT"miro-verification=6e1ca9ad6d0c2cd2e4186141265f23ed618cfe37"293
TXT"mixpanel-domain-verify=164dda91-31f4-41e8-a816-0f59b38fea30"293
TXT"notion-domain-verification=uKi5TAGxlhWMHG9uHKHkDY3cVc6zraAE1I44bILENlB"293
TXT"slack-domain-verification=9oO8P4Glf4252QJDOg4rHGs6KlSkBuI5ZVmWRO8d"293
TXT"stripe-verification=46F7B88485621DC18923B43D12E90E6CDBCE232F2FEBCF084E6EFA91F6BA707D"293
TXT"traction-guest=6882b04e-4188-4ff9-8bb4-bff5a3d358e6"293
TXT"traction-guest=a4d0248d-fe01-4222-8fcc-33f68323e667"293
TXT"v=spf1 ip4:199.16.156.0/22 ip4:199.59.148.0/22 ip4:8.25.194.0/23 ip4:8.25.196.0/23 ip4:204.92.114.203 ip4:204.92.114.204/31 include:_spf.google.com include:_thirdparty.twitter.com -all"293
TXT"wrike-verification=MjU4MTA5MjoyN2UzNDc1MjU3MDZiZTY4NjBiNzliNDQ2OTUwNWY3NmM5NDgyMTBlYzFkNTcwYTE2YWNmZDdkNTY2ZmE4Yzlh"293

Checks

  • ✓ TTLs within range #32
    TTLs: A 5m, MX 5m, NS 3h53m19s. The NS TTL at the parent is 2d and in the zone 3h53m19s; 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