IP Lookup

Reverse DNS, location, network block, ASN, and registration data for a public IP address.

Checked 2026-09-01T05:51:52+00:00 · · fresh lookup

IP
216.73.216.151
Version
IPv4
Public
Yes
Reverse DNS
Country
US
Location
Columbus, Ohio
ASN / Org
AS16509 Amazon.com, Inc.
Network block
216.73.192.0 – 216.73.219.255 (7,168 addresses)

Registration (RDAP)

Network
AWS-ANTHROPIC
Handle
NET-216-73-216-0-1
Range
216.73.216.0 – 216.73.219.255
Type
ASSIGNMENT
Organization
Anthropic, PBC
Registered
2024-06-05 UTC
Updated
2024-06-05 UTC
Status
active
Abuse contact
[email protected]
Raw RDAP JSON
{
    "arin_originas0_originautnums": [],
    "cidr0_cidrs": [
        {
            "v4prefix": "216.73.216.0",
            "length": 22
        }
    ],
    "endAddress": "216.73.219.255",
    "entities": [
        {
            "entities": [
                {
                    "events": [
                        {
                            "eventAction": "last changed",
                            "eventDate": "2026-08-18T02:54:11-04:00"
                        },
                        {
                            "eventAction": "registration",
                            "eventDate": "2023-07-31T16:45:12-04:00"
                        }
                    ],
                    "handle": "ANTHR5-ARIN",
                    "links": [
                        {
                            "href": "https://rdap.arin.net/registry/entity/ANTHR5-ARIN",
                            "rel": "self",
                            "type": "application/rdap+json",
                            "value": "https://rdap.arin.net/registry/ip/216.73.216.151"
                        },
                        {
                            "href": "https://whois.arin.net/rest/poc/ANTHR5-ARIN",
                            "rel": "alternate",
                            "type": "application/xml",
                            "value": "https://rdap.arin.net/registry/ip/216.73.216.151"
                        }
                    ],
                    "objectClassName": "entity",
                    "port43": "whois.arin.net",
                    "roles": [
                        "technical",
                        "routing",
                        "administrative",
                        "noc",
                        "dns",
                        "abuse"
                    ],
                    "status": [
                        "validated"
                    ],
                    "vcardArray": [
                        "vcard",
                        [
                            [
                                "version",
                                [],
                                "text",
                                "4.0"
                            ],
                            [
                                "adr",
                                {
                                    "label": "548 Market St.\nPMB 90375\nSan Francisco\nCA\n94104-5401\nUnited States"
                                },
                                "text",
                                [
                                    "",
                                    "",
                                    "",
                                    "",
                                    "",
                                    "",
                                    ""
                                ]
                            ],
                            [
                                "fn",
                                [],
                                "text",
                                "Anthropic"
                            ],
                            [
                                "org",
                                [],
                                "text",
                                "Anthropic, PBC"
                            ],
                            [
                                "kind",
                                [],
                                "text",
                                "group"
                            ],
                            [
                                "email",
                                [],
                                "text",
                                "[email protected]"
                            ],
                            [
                                "tel",
                                {
                                    "type": [
                                        "work",
                                        "voice"
                                    ]
                                },
                                "text",
                                "+1-415-236-0599"
                            ]
                        ]
                    ]
                }
            ],
            "events": [
                {
                    "eventAction": "last changed",
                    "eventDate": "2023-08-22T17:10:25-04:00"
                },
                {
                    "eventAction": "registration",
                    "eventDate": "2023-07-31T16:51:11-04:00"
                }
            ],
            "handle": "AP-2440",
            "links": [
                {
                    "href": "https://rdap.arin.net/registry/entity/AP-2440",
                    "rel": "self",
                    "type": "application/rdap+json",
                    "value": "https://rdap.arin.net/registry/ip/216.73.216.151"
                },
                {
                    "href": "https://whois.arin.net/rest/org/AP-2440",
                    "rel": "alternate",
                    "type": "application/xml",
                    "value": "https://rdap.arin.net/registry/ip/216.73.216.151"
                }
            ],
            "objectClassName": "entity",
            "port43": "whois.arin.net",
            "roles": [
                "registrant"
            ],
            "vcardArray": [
                "vcard",
                [
                    [
                        "version",
                        [],
                        "text",
                        "4.0"
                    ],
                    [
                        "fn",
                        [],
                        "text",
                        "Anthropic, PBC"
                    ],
                    [
                        "adr",
                        {
                            "label": "548 Market St.\nPMB 90375\nSan Francisco\nCA\n94104-5401\nUnited States"
                        },
                        "text",
                        [
                            "",
                            "",
                            "",
                            "",
                            "",
                            "",
                            ""
                        ]
                    ],
                    [
                        "kind",
                        [],
                        "text",
                        "org"
                    ]
                ]
            ]
        }
    ],
    "events": [
        {
            "eventAction": "last changed",
            "eventDate": "2024-06-05T12:42:32-04:00"
        },
        {
            "eventAction": "registration",
            "eventDate": "2024-06-05T12:42:32-04:00"
        }
    ],
    "handle": "NET-216-73-216-0-1",
    "ipVersion": "v4",
    "links": [
        {
            "href": "https://rdap.arin.net/registry/ip/216.73.216.0",
            "rel": "self",
            "type": "application/rdap+json",
            "value": "https://rdap.arin.net/registry/ip/216.73.216.151"
        },
        {
            "href": "https://whois.arin.net/rest/net/NET-216-73-216-0-1",
            "rel": "alternate",
            "type": "application/xml",
            "value": "https://rdap.arin.net/registry/ip/216.73.216.151"
        },
        {
            "href": "https://rdap.arin.net/registry/ip/216.73.208.0/21",
            "rel": "up",
            "type": "application/rdap+json",
            "value": "https://rdap.arin.net/registry/ip/216.73.216.151"
        }
    ],
    "name": "AWS-ANTHROPIC",
    "notices": [
        {
            "description": [
                "By using the ARIN RDAP/Whois service, you are agreeing to the RDAP/Whois Terms of Use"
            ],
            "links": [
                {
                    "href": "https://www.arin.net/resources/registry/whois/tou/",
                    "rel": "terms-of-service",
                    "type": "text/html",
                    "value": "https://rdap.arin.net/registry/ip/216.73.216.151"
                }
            ],
            "title": "Terms of Service"
        },
        {
            "description": [
                "If you see inaccuracies in the results, please visit: "
            ],
            "links": [
                {
                    "href": "https://www.arin.net/resources/registry/whois/inaccuracy_reporting/",
                    "rel": "inaccuracy-report",
                    "type": "text/html",
                    "value": "https://rdap.arin.net/registry/ip/216.73.216.151"
                }
            ],
            "title": "Whois Inaccuracy Reporting"
        },
        {
            "description": [
                "Copyright 1997-2026, American Registry for Internet Numbers, Ltd."
            ],
            "title": "Copyright Notice"
        }
    ],
    "objectClassName": "ip network",
    "parentHandle": "NET-216-73-208-0-1",
    "port43": "whois.arin.net",
    "rdapConformance": [
        "nro_rdap_profile_0",
        "rdap_level_0",
        "cidr0",
        "arin_originas0"
    ],
    "startAddress": "216.73.216.0",
    "status": [
        "active"
    ],
    "type": "ASSIGNMENT"
}

About this tool

Look up a public IP address and see reverse DNS, country, city/region, the network (ASN/organization), the routed IP block, and registration details from the regional registry when available. Private and reserved ranges are not accepted.

What you get

  • Normalized IP and IPv4/IPv6 version
  • Whether the address is public
  • Reverse DNS hostnames when available
  • Country flag + code, city/region, and ASN/org when available
  • Network block (CIDR or start–end range) for the matching ASN allocation
  • RDAP registration summary — network name, range, organization, dates, abuse contact when published

How to use

Your IP is prefilled when possible. Edit the field or keep it, then click Lookup.

FAQ

How to look up IP address information?

Enter an IPv4 or IPv6 address to see reverse DNS, country flag, city and region when available, ASN, organization, and network range.

What is reverse DNS lookup?

Reverse DNS maps an IP to its PTR hostname—often reveals hosting provider naming patterns and mail server identity.

How to find ASN and organization for an IP?

The results show autonomous system number, ISP or company name, and the routed network block the address belongs to.

What geolocation data does IP lookup show?

Country, region, and city estimates appear with a flag icon—approximate location for routing and analytics, not a precise street address.

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