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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.

151.101.192.81

81.192.101.151.in-addr.arpa

Zone 151.in-addr.arpa20 queries in 0.7 s2026-11-09 05:35:01 UTC

  • Problem 81.192.101.151.in-addr.arpa doesn't exist (NXDOMAIN from 151.in-addr.arpa's nameservers).

Resolution trace

  1. .asked l.root-servers.net 199.7.83.425.7 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
  2. in-addr.arpa.asked a.in-addr-servers.arpa 199.180.182.5390 ms

    Referral to 151.in-addr.arpa. signed (1 DS)

    • rirns.arin.net 199.253.249.53 2620:38:2000::53
    • ns3.afrinic.net 204.61.216.100 2001:500:14:6100:ad::1
    • ns4.apnic.net 202.12.31.53 2001:dd8:12::53
    • pri.authdns.ripe.net 193.0.9.5 2a13:27c0:30::5
    • ns3.lacnic.net 200.3.13.14 2001:13c7:7002:3000::14

    No glue for rirns.arin.net, ns3.afrinic.net, ns4.apnic.net, pri.authdns.ripe.net, ns3.lacnic.net: addresses looked up via a resolver.

    200.10.60.53 failed: NOERROR

  3. 151.in-addr.arpa.asked rirns.arin.net 199.253.249.5394 ms

    NXDOMAIN: this name does not exist.

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 1.1.1.1NXDOMAIN
validated
Google 8.8.8.8NXDOMAIN
validated
Quad9 9.9.9.9NXDOMAIN
validated
OpenDNS 208.67.222.222NXDOMAIN
validated

Text dump

; DNS report for 81.192.101.151.in-addr.arpa (151.101.192.81)
; 2026-11-09 05:35:01 UTC, 20 queries in 0.67 s, zone 151.in-addr.arpa

;; FINDINGS
;  [ERROR] 81.192.101.151.in-addr.arpa doesn't exist (NXDOMAIN from 151.in-addr.arpa's nameservers).

;; TRACE
;  81.192.101.151.in-addr.arpa PTR
;  . @l.root-servers.net (199.7.83.42) 5.7 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. @a.in-addr-servers.arpa (199.180.182.53) 90 ms [NOERROR qr]: referral to 151.in-addr.arpa.
151.in-addr.arpa.		NS	rirns.arin.net.	; 199.253.249.53 2620:38:2000::53
151.in-addr.arpa.		NS	ns3.afrinic.net.	; 204.61.216.100 2001:500:14:6100:ad::1
151.in-addr.arpa.		NS	ns4.apnic.net.	; 202.12.31.53 2001:dd8:12::53
151.in-addr.arpa.		NS	pri.authdns.ripe.net.	; 193.0.9.5 2a13:27c0:30::5
151.in-addr.arpa.		NS	ns3.lacnic.net.	; 200.3.13.14 2001:13c7:7002:3000::14
151.in-addr.arpa.	86400	IN	DS	33422 13 2 5BB123266E18D985C75AD39A56A98D2ACD9F9D5ED429594E842F2234F1CA342A
;  151.in-addr.arpa. @rirns.arin.net (199.253.249.53) 94 ms [NXDOMAIN qr aa]: NXDOMAIN

;; PUBLIC RESOLVERS
;  Cloudflare PTR   NXDOMAIN  ad
;  Google     PTR   NXDOMAIN  ad
;  Quad9      PTR   NXDOMAIN  ad
;  OpenDNS    PTR   NXDOMAIN  ad