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DNS lookup

Everything DNS says about a domain: traced from the root servers down, every record type asked of the domain's own nameservers, each nameserver checked, then every hostname and policy record it points at followed, with SPF, DMARC, DKIM and DNSSEC checked along the way.

Try example.com, gmail.com, www.github.com, dnssec-failed.org, 1.1.1.1. A URL, e-mail address or IP address works too.

142.251.110.100

100.110.251.142.in-addr.arpa

Zone 251.142.in-addr.arpa92 queries in 0.6 s2026-11-09 05:24:57 UTCNot DNSSEC-signed

WHOIS for 142.251.110.100 →TextJSON
  • Warning Nameservers disagree on the SOA serial (1016687210 on ns1.google.com, ns2.google.com, ns3.google.com, ns4.google.com; 1016230534 on ns3.google.com). Normal when two DNS providers serve the zone, each numbering its own copy; otherwise some servers haven't picked up the latest change.
  • Note 251.142.in-addr.arpa isn't signed with DNSSEC, so resolvers can't tell forged answers from real ones.

Records

Asked directly of ns4.google.com (216.239.38.10), an authoritative server: no cache in between, so these are the live values.

PTR Reverse pointer

3600PTRbz-in-f100.1e100.net.
ANY query: 1 records
3600PTRbz-in-f100.1e100.net.

No records of type A, AAAA, CNAME, DNAME, NS, SOA, MX, TXT, CAA, HTTPS, SVCB, SRV, NAPTR, DS, DNSKEY, CDS, CDNSKEY, NSEC3PARAM, TLSA, SSHFP, LOC, HINFO, RP, URI, SPF, OPENPGPKEY, ZONEMD, CSYNC.

Resolution trace

  1. .asked f.root-servers.net 192.5.5.2416.2 ms

    Referral to in-addr.arpa. signed (4 DS)

    • a.in-addr-servers.arpa 199.180.182.53 2620:37:e000::53
    • b.in-addr-servers.arpa 199.253.183.183 2001:500:87::87
    • c.in-addr-servers.arpa 196.216.169.10 2001:43f8:110::10
    • d.in-addr-servers.arpa 200.10.60.53 2001:13c7:7010::53
    • e.in-addr-servers.arpa 203.119.86.101 2001:dd8:6::101
    • f.in-addr-servers.arpa 193.0.9.1 2a13:27c0:30::1

    193.0.14.129 failed: NOERROR

  2. in-addr.arpa.asked f.in-addr-servers.arpa 193.0.9.111 ms

    Referral to 142.in-addr.arpa. signed (1 DS)

    • r.arin.net 199.180.180.63 2001:500:f0::63
    • u.arin.net 204.61.216.50 2001:500:14:6050:ad::1
    • x.arin.net 199.180.180.63 2001:500:f0::63
    • y.arin.net 192.82.134.30 2001:500:127::30
    • z.arin.net 199.180.180.63 2001:500:f0::63
    • arin.authdns.ripe.net 193.0.9.10 2a13:27c0:30::10

    No glue for r.arin.net, u.arin.net, x.arin.net, y.arin.net, z.arin.net, arin.authdns.ripe.net: addresses looked up via a resolver.

  3. 142.in-addr.arpa.asked u.arin.net 204.61.216.505.8 ms

    Referral to 251.142.in-addr.arpa. unsigned delegation

    • ns1.google.com 216.239.32.10 2001:4860:4802:32::a
    • ns2.google.com 216.239.34.10 2001:4860:4802:34::a
    • ns3.google.com 216.239.36.10 2001:4860:4802:36::a
    • ns4.google.com 216.239.38.10 2001:4860:4802:38::a

    No glue for ns1.google.com, ns2.google.com, ns3.google.com, ns4.google.com: addresses looked up via a resolver.

    193.0.9.10 failed: NOERROR

  4. 251.142.in-addr.arpa.asked ns4.google.com 216.239.38.106.2 ms

    Answer (authoritative):

    100.110.251.142.in-addr.arpa.3600PTRbz-in-f100.1e100.net.

Nameservers

Every address of every nameserver, asked for 251.142.in-addr.arpa's SOA. "Parent" means the 142.in-addr.arpa zone delegates to it; "zone" means 251.142.in-addr.arpa lists it itself.

NameserverListed inAddressStatusSerialTime
ns1.google.comparent216.239.32.10 glueauthoritative101668721013 ms
2001:4860:4802:32::a glueauthoritative101668721013 ms
ns2.google.comparent216.239.34.10 glueauthoritative101668721027 ms
2001:4860:4802:34::a glueauthoritative101668721027 ms
ns3.google.comparent216.239.36.10 glueauthoritative101623053414 ms
2001:4860:4802:36::a glueauthoritative101668721013 ms
ns4.google.comparent216.239.38.10 glueauthoritative10166872106.7 ms
2001:4860:4802:38::a glueauthoritative10166872106.6 ms

DNSSEC

251.142.in-addr.arpa isn't signed: no DS at the parent and no DNSKEY in the zone.

Hosts and reverse DNS

Every hostname the records point at, resolved to its addresses; each address's PTR (reverse DNS), with ✓ where the PTR name resolves back to the same address.

HostAddressReverse DNS (PTR)
ns1.google.com
nameserver
216.239.32.10ns1.google.com ✓
2001:4860:4802:32::ans1.google.com ✓
ns2.google.com
nameserver
216.239.34.10ns2.google.com ✓
2001:4860:4802:34::ans2.google.com ✓
ns3.google.com
nameserver
216.239.36.10ns3.google.com ✓
2001:4860:4802:36::ans3.google.com ✓
ns4.google.com
nameserver
216.239.38.10ns4.google.com ✓
2001:4860:4802:38::ans4.google.com ✓
bz-in-f100.1e100.net
PTR target
142.251.110.100bz-in-f100.1e100.net ✓
2a00:1450:4001:c1f::64bz-in-f100.1e100.net ✓

Public resolvers

What four public resolvers answer right now, from their caches. Highlighted values differ from the authoritative answer: either a recent change they haven't picked up yet (the TTL says how long until they do), or, for A and AAAA, a CDN or geo-routed site handing each resolver location its own addresses.

ResolverPTR
Cloudflare 1.1.1.1bz-in-f100.1e100.net.
TTL 455
Google 8.8.8.8bz-in-f100.1e100.net.
TTL 2272
Quad9 9.9.9.9bz-in-f100.1e100.net.
TTL 3600
OpenDNS 208.67.222.222bz-in-f100.1e100.net.
TTL 3600

Text dump

; DNS report for 100.110.251.142.in-addr.arpa (142.251.110.100)
; 2026-11-09 05:24:57 UTC, 92 queries in 0.64 s, zone 251.142.in-addr.arpa

;; FINDINGS
;  [WARN] Nameservers disagree on the SOA serial (1016687210 on ns1.google.com, ns2.google.com, ns3.google.com, ns4.google.com; 1016230534 on ns3.google.com). Normal when two DNS providers serve the zone, each numbering its own copy; otherwise some servers haven't picked up the latest change.
;  [INFO] 251.142.in-addr.arpa isn't signed with DNSSEC, so resolvers can't tell forged answers from real ones.

;; RECORDS (authoritative, from ns4.google.com (216.239.38.10))
100.110.251.142.in-addr.arpa.	3600	IN	PTR	bz-in-f100.1e100.net.

;; TRACE
;  100.110.251.142.in-addr.arpa PTR
;  . @f.root-servers.net (192.5.5.241) 6.2 ms [NOERROR qr]: referral to in-addr.arpa.
in-addr.arpa.		NS	a.in-addr-servers.arpa.	; 199.180.182.53 2620:37:e000::53
in-addr.arpa.		NS	b.in-addr-servers.arpa.	; 199.253.183.183 2001:500:87::87
in-addr.arpa.		NS	c.in-addr-servers.arpa.	; 196.216.169.10 2001:43f8:110::10
in-addr.arpa.		NS	d.in-addr-servers.arpa.	; 200.10.60.53 2001:13c7:7010::53
in-addr.arpa.		NS	e.in-addr-servers.arpa.	; 203.119.86.101 2001:dd8:6::101
in-addr.arpa.		NS	f.in-addr-servers.arpa.	; 193.0.9.1 2a13:27c0:30::1
in-addr.arpa.	86400	IN	DS	47054 8 2 5CAFCCEC201D1933B4C9F6A9C8F51E51F3B39979058AC21B8DF1B1F281CBC6F2
in-addr.arpa.	86400	IN	DS	53696 8 2 13E5501C56B20394DA921B51412D48B7089C5EB6957A7C58553C4D4D424F04DF
in-addr.arpa.	86400	IN	DS	54956 8 2 E0E2BF5CFBD66572CA05EC18267D91509BA6A9405AF05C3FD4141DFA45200C08
in-addr.arpa.	86400	IN	DS	63982 8 2 AAF4FB5D213EF25AE44679032EBE3514C487D7ABD99D7F5FEC3383D030733C73
;  in-addr.arpa. @f.in-addr-servers.arpa (193.0.9.1) 11 ms [NOERROR qr]: referral to 142.in-addr.arpa.
142.in-addr.arpa.		NS	r.arin.net.	; 199.180.180.63 2001:500:f0::63
142.in-addr.arpa.		NS	u.arin.net.	; 204.61.216.50 2001:500:14:6050:ad::1
142.in-addr.arpa.		NS	x.arin.net.	; 199.180.180.63 2001:500:f0::63
142.in-addr.arpa.		NS	y.arin.net.	; 192.82.134.30 2001:500:127::30
142.in-addr.arpa.		NS	z.arin.net.	; 199.180.180.63 2001:500:f0::63
142.in-addr.arpa.		NS	arin.authdns.ripe.net.	; 193.0.9.10 2a13:27c0:30::10
142.in-addr.arpa.	86400	IN	DS	12466 8 2 A272300DF1C5F7BCC360A7D2050428B6D2981D143F35A1CFAF88650E37ABAC9E
;  142.in-addr.arpa. @u.arin.net (204.61.216.50) 5.8 ms [NOERROR qr]: referral to 251.142.in-addr.arpa.
251.142.in-addr.arpa.		NS	ns1.google.com.	; 216.239.32.10 2001:4860:4802:32::a
251.142.in-addr.arpa.		NS	ns2.google.com.	; 216.239.34.10 2001:4860:4802:34::a
251.142.in-addr.arpa.		NS	ns3.google.com.	; 216.239.36.10 2001:4860:4802:36::a
251.142.in-addr.arpa.		NS	ns4.google.com.	; 216.239.38.10 2001:4860:4802:38::a
;  251.142.in-addr.arpa. @ns4.google.com (216.239.38.10) 6.2 ms [NOERROR qr aa]: answer
100.110.251.142.in-addr.arpa.	3600	IN	PTR	bz-in-f100.1e100.net.

;; NAMESERVERS (SOA asked of each address)
;  ns1.google.com [parent]
;    216.239.32.10                           ok                        1016687210  13 ms
;    2001:4860:4802:32::a                    ok                        1016687210  13 ms
;  ns2.google.com [parent]
;    216.239.34.10                           ok                        1016687210  27 ms
;    2001:4860:4802:34::a                    ok                        1016687210  27 ms
;  ns3.google.com [parent]
;    216.239.36.10                           ok                        1016230534  14 ms
;    2001:4860:4802:36::a                    ok                        1016687210  13 ms
;  ns4.google.com [parent]
;    216.239.38.10                           ok                        1016687210  6.7 ms
;    2001:4860:4802:38::a                    ok                        1016687210  6.6 ms

;; DNSSEC: unsigned

;; HOSTS
;  ns1.google.com (nameserver)
;    216.239.32.10                           PTR ns1.google.com (confirmed)
;    2001:4860:4802:32::a                    PTR ns1.google.com (confirmed)
;  ns2.google.com (nameserver)
;    216.239.34.10                           PTR ns2.google.com (confirmed)
;    2001:4860:4802:34::a                    PTR ns2.google.com (confirmed)
;  ns3.google.com (nameserver)
;    216.239.36.10                           PTR ns3.google.com (confirmed)
;    2001:4860:4802:36::a                    PTR ns3.google.com (confirmed)
;  ns4.google.com (nameserver)
;    216.239.38.10                           PTR ns4.google.com (confirmed)
;    2001:4860:4802:38::a                    PTR ns4.google.com (confirmed)
;  bz-in-f100.1e100.net (PTR target)
;    142.251.110.100                         PTR bz-in-f100.1e100.net (confirmed)
;    2a00:1450:4001:c1f::64                  PTR bz-in-f100.1e100.net (confirmed)

;; PUBLIC RESOLVERS
;  Cloudflare PTR   bz-in-f100.1e100.net.  ttl 455
;  Google     PTR   bz-in-f100.1e100.net.  ttl 2272
;  Quad9      PTR   bz-in-f100.1e100.net.  ttl 3600
;  OpenDNS    PTR   bz-in-f100.1e100.net.  ttl 3600