IP Lookup

What this tool does

The IP lookup shows who an IP address belongs to: the provider or company that manages it, the autonomous system number (ASN), the country and approximate city, plus the name set in reverse DNS. Use it to figure out where a strange hit in your logs came from, check that a VPN exits in the right country, or identify the server behind a website.

How to read the result

• Provider: the organization that owns the address block, such as an ISP, a cloud company or a university.
• ASN: the autonomous system number, a kind of ID for a network on the internet. All IPs from the same carrier usually share the same ASN.
• Approximate location: estimated from public databases. It shows the region where the provider registered the block, not a person's address.
• Reverse DNS (PTR): the name the IP's owner attached to it. Mail servers usually have a PTR; home connections typically get a generic name from the ISP.
• Type: public, private (local network), CGNAT or reserved. Private addresses do not appear on the internet and have no public owner.

Common situations

An unknown IP shows up in my server log. Check the provider and the ASN. Many hits come from cloud companies and search engines. If it is abuse, the provider usually has a contact for reports.

The location is wrong. Geolocation databases are often wrong at the city level, especially for mobile connections and CGNAT. The country and the provider are usually reliable.

The IP starts with 100.64 to 100.127. That is CGNAT: the provider shares one public IP among several customers. That is why port forwarding for remote access does not work on this kind of connection.

Frequently asked questions

Can you find someone's address from their IP?

No. An IP shows the provider and an approximate region. Customer details stay with the provider and can only be released by court order.

What is an ASN?

It is the autonomous system number, which identifies a network on the internet, such as a carrier's or a cloud company's. All IP blocks of that network are announced under it.

What is reverse DNS?

It is DNS in reverse: instead of turning a name into an IP, it turns an IP into a name. It is set by the owner of the block and is widely used by mail servers.

Why does my IP show up in another city?

Geolocation databases use the region where the provider registered the address block. With mobile connections and CGNAT, it is common to see the city of the carrier's hub.

Does the lookup work with IPv6?

Yes. Enter the full or shortened IPv6 address, like 2001:4860:4860::8888.