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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.

52.101.40.3

3.40.101.52.in-addr.arpa

Zone 40.101.52.in-addr.arpa101 queries in 0.6 s2026-11-09 05:34:54 UTCNot DNSSEC-signed

WHOIS for 52.101.40.3 →TextJSON
  • Note 40.101.52.in-addr.arpa isn't signed with DNSSEC, so resolvers can't tell forged answers from real ones.

Records

Asked directly of ns1-09.azure-dns.com (13.107.236.9), an authoritative server: no cache in between, so these are the live values.

PTR Reverse pointer

10PTRmail-cy4pr03cu00203.inbound.protection.outlook.com.
ANY query: refused politely (RFC 8482)
300HINFO"RFC8482" ""

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 g.root-servers.net 192.112.36.424 ms

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

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

    193.0.14.129 failed: NOERROR

  2. in-addr.arpa.asked f.in-addr-servers.arpa 193.0.9.112 ms

    Referral to 52.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. 52.in-addr.arpa.asked u.arin.net 204.61.216.505.9 ms

    Referral to 101.52.in-addr.arpa. unsigned delegation

    • ns3-04.azure-dns.org 204.14.183.4 2a01:111:4000:700::4
    • ns1-04.azure-dns.com 13.107.236.4 2603:1061:0:700::4
    • ns2-04.azure-dns.net 150.171.21.4 2620:1ec:8ec:700::4
    • ns4-04.azure-dns.info 208.84.5.4 2620:1ec:bda:700::4

    No glue for ns3-04.azure-dns.org, ns1-04.azure-dns.com, ns2-04.azure-dns.net, ns4-04.azure-dns.info: addresses looked up via a resolver.

  4. 101.52.in-addr.arpa.asked ns4-04.azure-dns.info 208.84.5.46.3 ms

    Referral to 40.101.52.in-addr.arpa. unsigned delegation

    • ns1-09.azure-dns.com 13.107.236.9 2603:1061:0:700::9
    • ns2-09.azure-dns.net 150.171.21.9 2620:1ec:8ec:700::9
    • ns3-09.azure-dns.org 204.14.183.9 2a01:111:4000:700::9
    • ns4-09.azure-dns.info 208.84.5.9 2620:1ec:bda:700::9

    No glue for ns1-09.azure-dns.com, ns2-09.azure-dns.net, ns3-09.azure-dns.org, ns4-09.azure-dns.info: addresses looked up via a resolver.

    150.171.21.4 failed: NOERROR

  5. 40.101.52.in-addr.arpa.asked ns1-09.azure-dns.com 13.107.236.96.3 ms

    Answer (authoritative):

    3.40.101.52.in-addr.arpa.10PTRmail-cy4pr03cu00203.inbound.protection.outlook.com.

    150.171.21.9 failed: NOERROR

Nameservers

Every address of every nameserver, asked for 40.101.52.in-addr.arpa's SOA. "Parent" means the 101.52.in-addr.arpa zone delegates to it; "zone" means 40.101.52.in-addr.arpa lists it itself.

NameserverListed inAddressStatusSerialTime
ns1-09.azure-dns.comparent + zone13.107.236.9 glueauthoritative16.4 ms
2603:1061:0:700::9 glueauthoritative17.7 ms
ns2-09.azure-dns.netparent + zone150.171.21.9 glueauthoritative16.9 ms
2620:1ec:8ec:700::9 glueauthoritative17.6 ms
ns3-09.azure-dns.orgparent + zone204.14.183.9 glueauthoritative16.9 ms
2a01:111:4000:700::9 glueauthoritative17.7 ms
ns4-09.azure-dns.infoparent + zone208.84.5.9 glueauthoritative17.6 ms
2620:1ec:bda:700::9 glueauthoritative17.6 ms

DNSSEC

40.101.52.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)
ns1-09.azure-dns.com
nameserver
13.107.236.9ns1-09.azure-dns.com ✓
2603:1061:0:700::9ns1-09.azure-dns.com ✓
ns2-09.azure-dns.net
nameserver
150.171.21.9ns2-09.azure-dns.net ✓
2620:1ec:8ec:700::9ns2-09.azure-dns.net ✓
ns3-09.azure-dns.org
nameserver
204.14.183.9ns3-09.azure-dns.org ✓
2a01:111:4000:700::9ns3-09.azure-dns.org ✓
ns4-09.azure-dns.info
nameserver
208.84.5.9ns4-09.azure-dns.info ✓
2620:1ec:bda:700::9ns4-09.azure-dns.info ✓
mail-cy4pr03cu00203.inbound.protection.outlook.com
PTR target
52.101.40.3mail-cy4pr03cu00203.inbound.protection.outlook.com ✓

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 1.1.1.1mail-cy4pr03cu00203.inbound.protection.outlook.com.
TTL 10
Google 8.8.8.8mail-cy4pr03cu00203.inbound.protection.outlook.com.
TTL 10
Quad9 9.9.9.9mail-cy4pr03cu00203.inbound.protection.outlook.com.
TTL 10
OpenDNS 208.67.222.222mail-cy4pr03cu00203.inbound.protection.outlook.com.
TTL 10

Text dump

; DNS report for 3.40.101.52.in-addr.arpa (52.101.40.3)
; 2026-11-09 05:34:54 UTC, 101 queries in 0.61 s, zone 40.101.52.in-addr.arpa

;; FINDINGS
;  [INFO] 40.101.52.in-addr.arpa isn't signed with DNSSEC, so resolvers can't tell forged answers from real ones.

;; RECORDS (authoritative, from ns1-09.azure-dns.com (13.107.236.9))
3.40.101.52.in-addr.arpa.	10	IN	PTR	mail-cy4pr03cu00203.inbound.protection.outlook.com.

;; TRACE
;  3.40.101.52.in-addr.arpa PTR
;  . @g.root-servers.net (192.112.36.4) 24 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	f.in-addr-servers.arpa.	; 193.0.9.1 2a13:27c0:30::1
in-addr.arpa.		NS	e.in-addr-servers.arpa.	; 203.119.86.101 2001:dd8:6::101
in-addr.arpa.		NS	b.in-addr-servers.arpa.	; 199.253.183.183 2001:500:87::87
in-addr.arpa.		NS	a.in-addr-servers.arpa.	; 199.180.182.53 2620:37:e000::53
in-addr.arpa.		NS	d.in-addr-servers.arpa.	; 200.10.60.53 2001:13c7:7010::53
in-addr.arpa.	86400	IN	DS	63982 8 2 AAF4FB5D213EF25AE44679032EBE3514C487D7ABD99D7F5FEC3383D030733C73
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	54956 8 2 E0E2BF5CFBD66572CA05EC18267D91509BA6A9405AF05C3FD4141DFA45200C08
;  in-addr.arpa. @f.in-addr-servers.arpa (193.0.9.1) 12 ms [NOERROR qr]: referral to 52.in-addr.arpa.
52.in-addr.arpa.		NS	r.arin.net.	; 199.180.180.63 2001:500:f0::63
52.in-addr.arpa.		NS	u.arin.net.	; 204.61.216.50 2001:500:14:6050:ad::1
52.in-addr.arpa.		NS	x.arin.net.	; 199.180.180.63 2001:500:f0::63
52.in-addr.arpa.		NS	y.arin.net.	; 192.82.134.30 2001:500:127::30
52.in-addr.arpa.		NS	z.arin.net.	; 199.180.180.63 2001:500:f0::63
52.in-addr.arpa.		NS	arin.authdns.ripe.net.	; 193.0.9.10 2a13:27c0:30::10
52.in-addr.arpa.	86400	IN	DS	37915 8 2 6D174AB775ACBCD38EE742BD94EA0498FFCCC923E39033616593CDF365838C02
;  52.in-addr.arpa. @u.arin.net (204.61.216.50) 5.9 ms [NOERROR qr]: referral to 101.52.in-addr.arpa.
101.52.in-addr.arpa.		NS	ns3-04.azure-dns.org.	; 204.14.183.4 2a01:111:4000:700::4
101.52.in-addr.arpa.		NS	ns1-04.azure-dns.com.	; 13.107.236.4 2603:1061:0:700::4
101.52.in-addr.arpa.		NS	ns2-04.azure-dns.net.	; 150.171.21.4 2620:1ec:8ec:700::4
101.52.in-addr.arpa.		NS	ns4-04.azure-dns.info.	; 208.84.5.4 2620:1ec:bda:700::4
;  101.52.in-addr.arpa. @ns4-04.azure-dns.info (208.84.5.4) 6.3 ms [NOERROR qr]: referral to 40.101.52.in-addr.arpa.
40.101.52.in-addr.arpa.		NS	ns1-09.azure-dns.com.	; 13.107.236.9 2603:1061:0:700::9
40.101.52.in-addr.arpa.		NS	ns2-09.azure-dns.net.	; 150.171.21.9 2620:1ec:8ec:700::9
40.101.52.in-addr.arpa.		NS	ns3-09.azure-dns.org.	; 204.14.183.9 2a01:111:4000:700::9
40.101.52.in-addr.arpa.		NS	ns4-09.azure-dns.info.	; 208.84.5.9 2620:1ec:bda:700::9
;  40.101.52.in-addr.arpa. @ns1-09.azure-dns.com (13.107.236.9) 6.3 ms [NOERROR qr aa ad]: answer
3.40.101.52.in-addr.arpa.	10	IN	PTR	mail-cy4pr03cu00203.inbound.protection.outlook.com.

;; NAMESERVERS (SOA asked of each address)
;  ns1-09.azure-dns.com [parent+zone]
;    13.107.236.9                            ok                        1           6.4 ms
;    2603:1061:0:700::9                      ok                        1           7.7 ms
;  ns2-09.azure-dns.net [parent+zone]
;    150.171.21.9                            ok                        1           6.9 ms
;    2620:1ec:8ec:700::9                     ok                        1           7.6 ms
;  ns3-09.azure-dns.org [parent+zone]
;    204.14.183.9                            ok                        1           6.9 ms
;    2a01:111:4000:700::9                    ok                        1           7.7 ms
;  ns4-09.azure-dns.info [parent+zone]
;    208.84.5.9                              ok                        1           7.6 ms
;    2620:1ec:bda:700::9                     ok                        1           7.6 ms

;; DNSSEC: unsigned

;; HOSTS
;  ns1-09.azure-dns.com (nameserver)
;    13.107.236.9                            PTR ns1-09.azure-dns.com (confirmed)
;    2603:1061:0:700::9                      PTR ns1-09.azure-dns.com (confirmed)
;  ns2-09.azure-dns.net (nameserver)
;    150.171.21.9                            PTR ns2-09.azure-dns.net (confirmed)
;    2620:1ec:8ec:700::9                     PTR ns2-09.azure-dns.net (confirmed)
;  ns3-09.azure-dns.org (nameserver)
;    204.14.183.9                            PTR ns3-09.azure-dns.org (confirmed)
;    2a01:111:4000:700::9                    PTR ns3-09.azure-dns.org (confirmed)
;  ns4-09.azure-dns.info (nameserver)
;    208.84.5.9                              PTR ns4-09.azure-dns.info (confirmed)
;    2620:1ec:bda:700::9                     PTR ns4-09.azure-dns.info (confirmed)
;  mail-cy4pr03cu00203.inbound.protection.outlook.com (PTR target)
;    52.101.40.3                             PTR mail-cy4pr03cu00203.inbound.protection.outlook.com (confirmed)

;; PUBLIC RESOLVERS
;  Cloudflare PTR   mail-cy4pr03cu00203.inbound.protection.outlook.com.  ttl 10
;  Google     PTR   mail-cy4pr03cu00203.inbound.protection.outlook.com.  ttl 10
;  Quad9      PTR   mail-cy4pr03cu00203.inbound.protection.outlook.com.  ttl 10
;  OpenDNS    PTR   mail-cy4pr03cu00203.inbound.protection.outlook.com.  ttl 10