tweetdeck.com

Checked 22 October 2026, 11:13 UTC · via 8.8.8.8
✗Problems found
21 passed 5 warnings 1 failed 4 info

Registration

info

.com generic · CSC Corporate Domains, Inc. · expires 2027-05-16

Found

TLD
.com (generic)
ICANN policies apply
yes
Registrar
CSC Corporate Domains, Inc.
Registered
16 May 2008
Last changed
12 May 2026
Expires
16 May 2027
Status
client transfer prohibited, server delete prohibited, server transfer prohibited, server update prohibited
Registry nameservers
a.u08.twtrdns.net, b.u08.twtrdns.net, c.u08.twtrdns.net, d.u08.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 2027-05-16 #3
    The registration is valid until 2027-05-16 (206 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.u08.twtrdns.net, b.u08.twtrdns.net, c.u08.twtrdns.net, d.u08.twtrdns.net

Found

Parent zone
com
Delegation from
a.gtld-servers.net (192.5.6.30)
NS at the parent
a.u08.twtrdns.net, b.u08.twtrdns.net, c.u08.twtrdns.net, d.u08.twtrdns.net
NS in the zone
a.r08.twtrdns.net, a.u08.twtrdns.net, b.r08.twtrdns.net, b.u08.twtrdns.net, c.r08.twtrdns.net, c.u08.twtrdns.net, d.r08.twtrdns.net, d.u08.twtrdns.net
NameserverAddressesNetwork (AS)Glue
a.r08.twtrdns.net (zone only)205.251.196.52AS16509 AMAZON-02 - Amazon.com, Inc., US-
a.u08.twtrdns.net204.74.66.101AS12008 VERCARA - Vercara, LLC, US-
b.r08.twtrdns.net (zone only)205.251.192.103AS16509 AMAZON-02 - Amazon.com, Inc., US-
b.u08.twtrdns.net204.74.67.101AS12008 VERCARA - Vercara, LLC, US-
c.r08.twtrdns.net (zone only)205.251.195.152AS16509 AMAZON-02 - Amazon.com, Inc., US-
c.u08.twtrdns.net204.74.110.101AS12008 VERCARA - Vercara, LLC, US-
d.r08.twtrdns.net (zone only)205.251.199.230AS16509 AMAZON-02 - Amazon.com, Inc., US-
d.u08.twtrdns.net204.74.111.101AS12008 VERCARA - Vercara, LLC, US-

Checks

  • ✓ 4 nameservers #6
    Delegated to a.u08.twtrdns.net, b.u08.twtrdns.net, c.u08.twtrdns.net, d.u08.twtrdns.net.
  • !
    NS sets differ
    The nameservers at the parent and in the zone should be the same. Only in the zone: a.r08.twtrdns.net, b.r08.twtrdns.net, c.r08.twtrdns.net, d.r08.twtrdns.net. a.r08.twtrdns.net, a.u08.twtrdns.net, b.r08.twtrdns.net, b.u08.twtrdns.net, c.r08.twtrdns.net, c.u08.twtrdns.net, d.r08.twtrdns.net, d.u08.twtrdns.net report NS a.r08.twtrdns.net a.u08.twtrdns.net b.r08.twtrdns.net b.u08.twtrdns.net c.r08.twtrdns.net c.u08.twtrdns.net d.r08.twtrdns.net d.u08.twtrdns.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 8 IPv4 /24s and 0 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS12008 (VERCARA - Vercara, LLC, US): 4 addresses; AS16509 (AMAZON-02 - Amazon.com, Inc., US): 4 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.r08.twtrdns.net 205.251.196.52NOERROR, 3 ms, authoritativenoyes / yesrefused-
a.u08.twtrdns.net 204.74.66.101NOERROR, 3 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
b.r08.twtrdns.net 205.251.192.103NOERROR, 9 ms, authoritativenoyes / yesrefused-
b.u08.twtrdns.net 204.74.67.101NOERROR, 3 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
c.r08.twtrdns.net 205.251.195.152NOERROR, 3 ms, authoritativenoyes / yesrefused-
c.u08.twtrdns.net 204.74.110.101NOERROR, 3 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver
d.r08.twtrdns.net 205.251.199.230NOERROR, 9 ms, authoritativenoyes / yesrefused-
d.u08.twtrdns.net 204.74.111.101NOERROR, 13 ms, authoritativenoyes / yesrefusedUltraDNS Nameserver

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.u08.twtrdns.net: "UltraDNS Nameserver"; b.u08.twtrdns.net: "UltraDNS Nameserver"; c.u08.twtrdns.net: "UltraDNS Nameserver"; d.u08.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

fail

serial 2023030801 · primary a.u08.twtrdns.net

Found

Primary (MNAME)
a.u08.twtrdns.net
Contact (RNAME)
noc\@twitter.com
Serial
2023030801
Refresh / retry
3600 s / 600 s
Expire
604800 s
Negative TTL
60 s

Serial per nameserver

NameserverSerial
a.r08.twtrdns.net (205.251.196.52)2023030801
a.u08.twtrdns.net (204.74.66.101)2023188866
b.r08.twtrdns.net (205.251.192.103)2023030801
b.u08.twtrdns.net (204.74.67.101)2023188866
c.r08.twtrdns.net (205.251.195.152)2023030801
c.u08.twtrdns.net (204.74.110.101)2023188866
d.r08.twtrdns.net (205.251.199.230)2023030801
d.u08.twtrdns.net (204.74.111.101)2023188866

Checks

  • !
    Serials differ
    The nameservers serve different versions of the zone: 2023030801 on a.r08.twtrdns.net (205.251.196.52), b.r08.twtrdns.net (205.251.192.103), c.r08.twtrdns.net (205.251.195.152), d.r08.twtrdns.net (205.251.199.230); 2023188866 on a.u08.twtrdns.net (204.74.66.101), b.u08.twtrdns.net (204.74.67.101), c.u08.twtrdns.net (204.74.110.101), d.u08.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
  • !
    Unusual SOA timers
    negative caching TTL (minimum) 1m is outside 5m–1d (RFC 2308 recommends 1–3 hours). Current values: refresh 1h, retry 10m, expire 7d, negative TTL 1m.
    #23
  • ✓ Primary is a public nameserver #24
    The primary nameserver a.u08.twtrdns.net is one of the listed nameservers.
  • ✗
    Invalid contact address
    The SOA RNAME "noc\\@twitter.com" contains an @; it must be written with a dot instead (hostmaster.example.com).
    #25
  • ✓ Date-based serial #26
    The serial 2023030801 follows the YYYYMMDDnn convention (2023-03-08).

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

24 records at the apex

Found

Read from
205.251.196.52:53
TypeValueTTL
SOAa.u08.twtrdns.net. noc\@twitter.com. 2023030801 3600 600 604800 603600
NSa.r08.twtrdns.net.86400
NSa.u08.twtrdns.net.86400
NSb.r08.twtrdns.net.86400
NSb.u08.twtrdns.net.86400
NSc.r08.twtrdns.net.86400
NSc.u08.twtrdns.net.86400
NSd.r08.twtrdns.net.86400
NSd.u08.twtrdns.net.86400
A104.244.42.683600
A104.244.42.1323600
A104.244.42.43600
A104.244.42.1963600
MX10 aspmx.l.google.com.3600
MX20 alt1.aspmx.l.google.com.3600
MX20 alt2.aspmx.l.google.com.3600
MX30 aspmx2.googlemail.com.3600
MX30 aspmx3.googlemail.com.3600
MX30 aspmx4.googlemail.com.3600
MX30 aspmx5.googlemail.com.3600
TXT"3l4n67d8rm30kt0sdkvrfxlsy29848t9"3600
TXT"_c496glevzl0ajebcz5cceq0ppqwitiq"3600
TXT"rx1g82x0k1qq9cl4nfqnprbrq8yt55cy"3600
TXT"v=spf1 include:aspmx.googlemail.com include:amazonses.com ~all"3600

Checks

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