Whether PC, laptop, server or smartphone – every device that goes online has an IP address. As a user, IP addresses are used continuously, but few people are aware of this. As long as the Internet connection works, most people don’t care about their own IP address. However, there are also situations in which you have to enter your IP address. Users are often at a loss and ask themselves: What is an IP address? What is my own IP address? How can I find out my IP address?

At IPJack you will find answers to all the important questions about IP addresses. IPJack also allows you to find out your IP address at a glance and find out important information about your connection free of charge.

What is an IP address?

In a networked world where computers and devices communicate with each other, it is important to know the exact address of each device so that it can be addressed. This exact address is called an IP address. Named after the Internet transmission protocol TCP/IP, the IP address is the address that uniquely identifies a computer in the network. In order to address it, each device in the network needs its own IP address. Similar to how you reach your partner via his address when sending mail, IP addresses can be used to address data packets in such a way that they reach the desired recipient. The IP address is therefore the address of the device or computer in the network. The data packets are distributed to the correct IP address via so-called routers, which act similarly to post offices and send the information in the desired direction. Unlike postal addresses, IP addresses are not bound to a specific location.

IP addresses are divided into certain areas that differ according to geographical region and provider. The IP address can therefore be used to identify from where and via which provider a user accesses the Internet. The IP address also shows the version of the browser and operating system used.

How is an IP address structured?

Basically, IP addresses are represented as a string of numbers or character combinations. A distinction is made between two standards, the IPv4 addresses and the IPv6 addresses:

  • IPv4 addresses consist of four numbers in the range between 0 and 255, separated by dots. An example of an IPv4 address could be The 4 number blocks of an IPv4 address can be used to represent a total of 32 bits, i.e. 2³² or 4,294,967,296 addresses. In the early days of the Internet, it was thought that this number was sufficient.
  • IPv6 addresses consist of eight character blocks, which can contain numbers as well as letters. An example is the address 2001:0000:3238:DFE1:0063:0000:0000:FEFB. To simplify the address, successive blocks containing only zeros can be omitted and replaced by a double colon and individual blocks containing zeros by a 0. In our example, the correct spelling would be 2001:0:3238:DFE1:63::FEFB. The IPv6 standard uses 128 bits to store addresses, so 2128 = 25616 addresses can be represented. This means that almost every grain of sand on earth can be addressed.

Since IP addresses, i.e. the actual addresses of the individual computers and website servers, are difficult to remember, the so-called Domain Name System (DNS) was introduced, in which websites are assigned their own domain names. The DNS is a worldwide directory system that knows the IP address for each registered domain (i.e. can resolve names into addresses) in order to enable access to web pages, e-mails or FTP. The user’s computer determines in the Domain Name System (DNS) which IP address belongs to this domain name and establishes the connection with the respective web server.

How can the IP address be determined?

To determine the IP address of a computer, enter the command ipconfig in the Windows command prompt. If you are using a router, however, you will only see your local (internal) IP address. This address is not visible to the outside world. You can determine your external IP address, for example, via our website IPJack.com.

What are the IP addresses?

IP addresses can be differentiated according to different criteria. For example, there are external and internal IP addresses as well as dynamic and static IP addresses.

External and local IP addresses

An external IP address is the address with which the respective router or server or computer travels on the Internet. The external IP is assigned by the provider from an address block assigned to him. Unlike the telephone number or postal address, this can change.

Local or internal IP addresses are assigned by the router in the home or company network. Each device in the network has its own IP address. The router obtains its external IP address from the provider and assigns internal IP addresses to the connected devices in order to address them specifically.

Dynamic and static IP addresses

We speak of a dynamic IP address when a user is assigned a new IP address from the provider’s pool each time he connects to the network via the provider’s DHCP server (Dynamic Host Configuration Protocol). The address therefore changes dynamically. For example, the Internet Service Provider provides a constantly changing but unique IP address that nobody else in the world is using at this time. This has the particular advantage that fewer IP addresses are required per customer. After all, all users are never online at the same time. This is also an advantage for users, as the use of dynamic IP addresses provides much better protection of privacy than the permanent use of a fixed or static IP address.

A static IP address is an IP that remains unchanged for months or years and is used and transmitted every time an Internet user visits the Internet. With a fixed or static IP, terminals can always be reached at the same address. The fixed IP address is also initially assigned automatically, but is registered with the Internet provider and can be redefined if required.

Dynamic IP addresses do not make sense for Internet presences which the user should always reach at a specific address. For web servers, for example, static IP addresses assigned to a specific domain are used for each online presence. Static IP addresses can be immediately assigned to a data network and thus facilitate the addressing and administration of web servers. In addition, connected network components can also be reached externally via the Internet via static IP addresses. Users can therefore directly access drives, configuration interfaces, servers and (released) data of the respective network both at home and mobile via browser.

What is a DynDNS address?

DynDNS address or DDNS stands for Dynamic Domain Name System (Dynamic DNS) and is a technique for dynamically updating domains in the Domain Name System. This allows constantly changing IP addresses of PCs, routers or home networks to be quickly assigned to a fixed domain entry.

In order to use DynDNS, users must register with a DynDNS service under a free name. The computer can also be reached under this name if the IP address of the connection changes or if the IP address is unknown.

What is a MAC address?

The MAC address (Media Access Control) is also referred to as the physical address. It is used to uniquely identify a device. Each network-enabled device receives a unique identification number, which is stored on the network adapter. The MAC address consists of numbers between 0 and 9 as well as letters between A and F.

Knowledge of the MAC address can be relevant in networks with several different components that are connected via LAN or WLAN. For example, WLAN routers can be set up so that only certain computers and components can access the Internet, while others are blocked from doing so.

How can the MAC address be determined?

As a rule, the MAC address (MAC ID) is shown on a sticker on the device or the network adapter. If this is not the case, the MAC address can be determined in the Windows prompt with the command “ipconfig/all”. (Mac OS X via Terminal “ifconfig”)

Determine the current IP address with IPJack

If you want to know your current IP address, you can find it directly on IPJack. Here you can find out at a glance which IP address you are using on the network and under which IP address you can be found.