Made in / Donate

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.

142.251.20.83

83.20.251.142.in-addr.arpa

Zone 251.142.in-addr.arpa92 queries in 0.8 s2026-11-09 05:45:11 UTCNot DNSSEC-signed

WHOIS for 142.251.20.83 →TextJSON
  • 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

3600PTRbx-in-f83.1e100.net.
ANY query: 1 records
3600PTRbx-in-f83.1e100.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 c.root-servers.net 192.33.4.1239 ms

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

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

    170.247.170.2 failed: NOERROR

  2. in-addr.arpa.asked c.in-addr-servers.arpa 196.216.169.10166 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

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

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

    193.0.9.10 failed: NOERROR

  4. 251.142.in-addr.arpa.asked ns1.google.com 216.239.32.1013 ms

    Answer (authoritative):

    83.20.251.142.in-addr.arpa.3600PTRbx-in-f83.1e100.net.

    216.239.36.10 failed: NOERROR

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 glueauthoritative101668721026 ms
2001:4860:4802:34::a glueauthoritative101668721026 ms
ns3.google.comparent216.239.36.10 glueauthoritative101668721013 ms
2001:4860:4802:36::a glueauthoritative101668721013 ms
ns4.google.comparent216.239.38.10 glueauthoritative10166872106.3 ms
2001:4860:4802:38::a glueauthoritative10166872106.4 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 ✓
bx-in-f83.1e100.net
PTR target
142.251.20.83bx-in-f83.1e100.net ✓
2a00:1450:4001:c17::53bx-in-f83.1e100.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 1.1.1.1bx-in-f83.1e100.net.
TTL 795
Google 8.8.8.8bx-in-f83.1e100.net.
TTL 1088
Quad9 9.9.9.9bx-in-f83.1e100.net.
TTL 3164
OpenDNS 208.67.222.222bx-in-f83.1e100.net.
TTL 3600

Text dump

; DNS report for 83.20.251.142.in-addr.arpa (142.251.20.83)
; 2026-11-09 05:45:11 UTC, 92 queries in 0.79 s, zone 251.142.in-addr.arpa

;; FINDINGS
;  [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))
83.20.251.142.in-addr.arpa.	3600	IN	PTR	bx-in-f83.1e100.net.

;; TRACE
;  83.20.251.142.in-addr.arpa PTR
;  . @c.root-servers.net (192.33.4.12) 39 ms [NOERROR qr]: referral to in-addr.arpa.
in-addr.arpa.		NS	c.in-addr-servers.arpa.	; 196.216.169.10 2001:43f8:110::10
in-addr.arpa.		NS	e.in-addr-servers.arpa.	; 203.119.86.101 2001:dd8:6::101
in-addr.arpa.		NS	a.in-addr-servers.arpa.	; 199.180.182.53 2620:37:e000::53
in-addr.arpa.		NS	f.in-addr-servers.arpa.	; 193.0.9.1 2a13:27c0:30::1
in-addr.arpa.		NS	b.in-addr-servers.arpa.	; 199.253.183.183 2001:500:87::87
in-addr.arpa.		NS	d.in-addr-servers.arpa.	; 200.10.60.53 2001:13c7:7010::53
in-addr.arpa.	86400	IN	DS	47054 8 2 5CAFCCEC201D1933B4C9F6A9C8F51E51F3B39979058AC21B8DF1B1F281CBC6F2
in-addr.arpa.	86400	IN	DS	63982 8 2 AAF4FB5D213EF25AE44679032EBE3514C487D7ABD99D7F5FEC3383D030733C73
in-addr.arpa.	86400	IN	DS	54956 8 2 E0E2BF5CFBD66572CA05EC18267D91509BA6A9405AF05C3FD4141DFA45200C08
in-addr.arpa.	86400	IN	DS	53696 8 2 13E5501C56B20394DA921B51412D48B7089C5EB6957A7C58553C4D4D424F04DF
;  in-addr.arpa. @c.in-addr-servers.arpa (196.216.169.10) 166 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	ns3.google.com.	; 216.239.36.10 2001:4860:4802:36::a
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	ns4.google.com.	; 216.239.38.10 2001:4860:4802:38::a
;  251.142.in-addr.arpa. @ns1.google.com (216.239.32.10) 13 ms [NOERROR qr aa]: answer
83.20.251.142.in-addr.arpa.	3600	IN	PTR	bx-in-f83.1e100.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  26 ms
;    2001:4860:4802:34::a                    ok                        1016687210  26 ms
;  ns3.google.com [parent]
;    216.239.36.10                           ok                        1016687210  13 ms
;    2001:4860:4802:36::a                    ok                        1016687210  13 ms
;  ns4.google.com [parent]
;    216.239.38.10                           ok                        1016687210  6.3 ms
;    2001:4860:4802:38::a                    ok                        1016687210  6.4 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)
;  bx-in-f83.1e100.net (PTR target)
;    142.251.20.83                           PTR bx-in-f83.1e100.net (confirmed)
;    2a00:1450:4001:c17::53                  PTR bx-in-f83.1e100.net (confirmed)

;; PUBLIC RESOLVERS
;  Cloudflare PTR   bx-in-f83.1e100.net.  ttl 795
;  Google     PTR   bx-in-f83.1e100.net.  ttl 1088
;  Quad9      PTR   bx-in-f83.1e100.net.  ttl 3164
;  OpenDNS    PTR   bx-in-f83.1e100.net.  ttl 3600