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.
151.101.0.81
81.0.101.151.in-addr.arpa
Zone 151.in-addr.arpa20 queries in 0.5 s2026-11-09 05:34:58 UTC
- Problem 81.0.101.151.in-addr.arpa doesn't exist (NXDOMAIN from 151.in-addr.arpa's nameservers).
Resolution trace
- .asked i.root-servers.net 192.36.148.175.9 ms
Referral to in-addr.arpa. signed (4 DS)
- a.in-addr-servers.arpa 199.180.182.53 2620:37:e000::53
- 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
- d.in-addr-servers.arpa 200.10.60.53 2001:13c7:7010::53
- b.in-addr-servers.arpa 199.253.183.183 2001:500:87::87
- f.in-addr-servers.arpa 193.0.9.1 2a13:27c0:30::1
- in-addr.arpa.asked f.in-addr-servers.arpa 193.0.9.112 ms
Referral to 151.in-addr.arpa. signed (1 DS)
- ns3.lacnic.net 200.3.13.14 2001:13c7:7002:3000::14
- 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
- rirns.arin.net 199.253.249.53 2620:38:2000::53
No glue for ns3.lacnic.net, ns3.afrinic.net, ns4.apnic.net, pri.authdns.ripe.net, rirns.arin.net: addresses looked up via a resolver.
- 151.in-addr.arpa.asked pri.authdns.ripe.net 193.0.9.512 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.
| Resolver | PTR |
|---|---|
| Cloudflare 1.1.1.1 | NXDOMAIN validated |
| Google 8.8.8.8 | NXDOMAIN validated |
| Quad9 9.9.9.9 | NXDOMAIN validated |
| OpenDNS 208.67.222.222 | NXDOMAIN validated |
Text dump
; DNS report for 81.0.101.151.in-addr.arpa (151.101.0.81) ; 2026-11-09 05:34:58 UTC, 20 queries in 0.48 s, zone 151.in-addr.arpa ;; FINDINGS ; [ERROR] 81.0.101.151.in-addr.arpa doesn't exist (NXDOMAIN from 151.in-addr.arpa's nameservers). ;; TRACE ; 81.0.101.151.in-addr.arpa PTR ; . @i.root-servers.net (192.36.148.17) 5.9 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 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 d.in-addr-servers.arpa. ; 200.10.60.53 2001:13c7:7010::53 in-addr.arpa. NS b.in-addr-servers.arpa. ; 199.253.183.183 2001:500:87::87 in-addr.arpa. NS f.in-addr-servers.arpa. ; 193.0.9.1 2a13:27c0:30::1 in-addr.arpa. 86400 IN DS 53696 8 2 13E5501C56B20394DA921B51412D48B7089C5EB6957A7C58553C4D4D424F04DF 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. @f.in-addr-servers.arpa (193.0.9.1) 12 ms [NOERROR qr]: referral to 151.in-addr.arpa. 151.in-addr.arpa. NS ns3.lacnic.net. ; 200.3.13.14 2001:13c7:7002:3000::14 151.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 rirns.arin.net. ; 199.253.249.53 2620:38:2000::53 151.in-addr.arpa. 86400 IN DS 33422 13 2 5BB123266E18D985C75AD39A56A98D2ACD9F9D5ED429594E842F2234F1CA342A ; 151.in-addr.arpa. @pri.authdns.ripe.net (193.0.9.5) 12 ms [NXDOMAIN qr aa]: NXDOMAIN ;; PUBLIC RESOLVERS ; Cloudflare PTR NXDOMAIN ad ; Google PTR NXDOMAIN ad ; Quad9 PTR NXDOMAIN ad ; OpenDNS PTR NXDOMAIN ad