What is my public IP address?

You can find detailed information about IP addresses, subents and so on in my article TCP/IP - adresy, masky, subnety a vypocty (it's in Czech language!).

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Ccbot 2.0

What I see here

The IP address shown above, is in most cases, the IP address of your (or your provider's) router/firewall/NAT device or, in some cases, the IP address of the proxy server. Only when you use a public IP address directly on your computer, the above address should be the address of your computer. But often you need to know your public IP address and not the private address of your computer, which you can easily find (see below).

What is an IP address

An IP (Internet Protocol) address is a logical address of a device in a computer network using IP protocol (works on Layer 3 of ISO/OSI model). IP addresses are used on the Internet. IP addresses are stored as 32-bit binary numbers, but they are displayed as four decimal numbers divided with a dot (dot-decimal notation), example An IP address indicates the logical location of a device. An IP address range is from to Public addresses are managed by IANA (Internet Assigned Numbers Authority) and blocks of addresses are allocated to Local Internet Registries. These address blocks correspondent to geological locations.

Note: I'm writing here about older and still in use Internet Protocol Version 4 (IPv4), but there is a new Version 6 of this protocol (IPv6) which uses 128 bits for the address and offers many more addresses.

Public IP addresses

Public IP addresses are a major part of IP addresses. These addresses are used on the internet or other WAN (Wide Area Network) and could be routed in these networks.

Private IP addresses

Private IP addresses are used on a LAN (Local Area Network) and if you want to communicate to the internet you must translate this address to a public IP address. A common solution for address translation is NAT (Network Address Translation).

Private addresses are from to, from to and from to

Note: Other special addresses are Localhost Loopback Address from to, Zeroconf Address from to, Multicast Address from to

If you want to find an IP address of your computer (often private address), you can use a command ipconfig or ipconfig /all on Windows OS.