What is an IP Address?
An IP (Internet Protocol) address is used to identify devices on a network. Every device connected to the Internet is assigned a globally unique IP address. Routers use the address information to find the way in the network. Depending on whether an address is intended for an individual terminal device or a group of devices, there are unicast, multicast and broadcast addresses.
Two different versions of IP addresses
- An IPv4 address consists of four numbers that can have values from 0 to 255, each separated by a period. For example, the IP address 126.96.36.199 is a valid IPv4 address.
- An IPv6 address consists of several blocks that can contain numbers and letters, each separated by a colon. For example, the IP address 5: 9: 0: 1: 0: edgd: c1b9: 281 is a valid IPv6 address.
Several IP addresses can be assigned to a single network device at the same time. For example, a router in a home network has at least two IP addresses: a public IP address and a private IP address. The public IP address is used to communicate with devices on the Internet, while the private IP address is used to communicate with devices on the network. A network device can also have both an IPv4 address and an IPv6 address at the same time.
Three different types of IP addresses
- Unicast addresses are intended for a specific recipient. A data packet with a unicast is only sent to its chosen recipient.
- Multicast addresses intended for a group of devices. All endpoints of a multicast group receive data packets with these addresses.
- Data packets with broadcast addresses are delivered to all devices in a network or subnet.
Relationship between IP addresses and domain names
Since humans can easily remember speech instead of numbers, the World Wide Web uses domain names. The actual routing that takes place is based on the IP addresses. The Domain Name System (DNS) provides the IP address of a domain name entered by a user. It is a public directory that contains all the assignments of domain names and IP addresses on the Internet.