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What is my IP address?
1&1 IP-Check

Your IP is:

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What you should know about IP addresses

  • What is an IP address?

    The IP address ensures that data arrives where it is supposed to. Every computer that is connected to the Internet is part of a network. Within this network data is constantly sent and received. The IP address is a kind of individual identification number that enables targeted data exchange. For example, if you open a website, your browser transmits your IP address to the webserver of the website. The web server then knows exactly where to send the data. Our IP-Checker can show you this public IP address. As the IP address is provided by the server, it is not possible to change an IP address so it contains a specific sequence of numbers. However, restarting the router does cause a new random address to be reissued by the provider.

    Beyond this, internal IP addresses are assigned within local networks and are not outwardly visible. This means that each device that dials in to a private wireless network is allocated its own IP address. The router automatically generates an IP address that changes with each browsing session. The Windows "ipconfig" command allows you to access the address data of a device in a local network. Mac OS users must enter "ipconfig" in the terminal. The router itself also has an IP address, which can be viewed using the same command. The IP address of the router is often called the standard gateway and consists of a static sequence of numbers, commonly or You can set up a fixed IP address in the network settings.
  • How is my IP address determined?

    Usually the IP address is generated dynamically with every new browsing session through the Internet provider. This means that every new dial-up generates a new IP address or at least once a day. This has the advantage that the assignment of IP addresses is done more efficiently, as all users are never online at the same time, and the dynamic method can also take the unused addresses into consideration. Dynamic IP addresses also contribute to online safety, as they make identification and external attacks more difficult.

    Along with dynamic IP addresses, static addresses are also used—most commonly if the IP in question belongs to a homepage, as websites are supposed to be easy to find for the users. This is why the Domain Name System (DNS) was introduced. A domain like is much easier to remember than a seemingly meaningless number sequence. Every domain in turn leads to a web server with a fixed IP Address.
  • How is my IP address put together?

    When it comes to IP addresses, we differentiate between IPv4 and IPv5 addresses. An IPv4 address consists of four blocks of numbers divided by a full stop. In each block, any number between 0 and 225 can be used, which results in roughly 4,3 billion possible addresses. As the Internet has grown so rapidly over the last few years, and will continue to grow in the future, this number is quickly becoming insufficient. This is why the IPv6 format is currently being introduced as the new norm, which can generate roughly sextillion new addresses. The structure of IPv6 addresses is less clear, as it uses both numbers and letters in eight separate blocks.

    Your IP address is never just a ransom sequence of numbers or letters. Specific IP areas are allocated to certain providers or to big companies. There is no country code, like the one found in telephone numbers, when it comes to IP addresses though. Rather the IP address can be found through the so called dial-up node. It also shows which browser and operating system is being used. The Internet Provider can receive information on the user's online behavior during a web browsing session through the IP address. The regulations on what happens to this data after the browsing session is finished also varies depending on the country.
  • How are local networks and IP addresses related?

    For security reasons, a router will block attempts to externally access a local network. However, in certain cases allowing external access can be beneficial. For example, this allows for you to provide others access to your network via File Transfer Protocol (FTP), and thereby set up a server to transfer your files. Everyone who would like to provide their friends with a small gaming server in their home network needs the IP address to do so. Minecraft and other games specifically offer game server software for this purpose.

    To subvert the router's firewall, so called "ports" are enabled to allow external access. To dial in to the game server, gamers need the IP address of the server. The exact configuration of the firewall depends on both the operating system and on the game server or FTP software.