IP addresses (Internet Protocol Addresses) are the foundation of communication in network infrastructure. Whether you work with IPv4 or IPv6, understanding the classification and purpose of various types of IP addresses and their ranges is essential.

Public IP Addresses

Public IP addresses are unique across the entire internet and enable direct communication with other devices online. These addresses are assigned by the IANA (Internet Assigned Numbers Authority) and regional registries (RIR), such as RIPE NCC for Europe.

• Example: 93.184.216.34 (address of the server example.com).

• Usage: Web servers, email servers, services accessible on the internet.

Private IP Addresses

Private IP addresses are used within local networks, such as home or corporate networks. These addresses are not accessible from the internet and require NAT (Network Address Translation) for communication outside the local network.

Ranges of private IP addresses (according to RFC 1918):

• 10.0.0.0 – 10.255.255.255 (Class A)

• 172.16.0.0 – 172.31.255.255 (Class B)

• 192.168.0.0 – 192.168.255.255 (Class C)

Examples of usage: Routers, IoT devices, printers.

Reserved IP Addresses

Reserved addresses serve specific purposes and are not intended for general use.

• 0.0.0.0/8: Undefined addresses.

• 127.0.0.0/8: Loopback addresses, such as 127.0.0.1 (refers to the local machine).

• 169.254.0.0/16: APIPA (Automatic Private IP Addressing), automatically assigned when DHCP fails.

• 192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24: Testing and documentation ranges.

• 224.0.0.0 – 239.255.255.255: Multicast addresses.

Multicast IP Addresses

Multicast addresses allow data to be sent to multiple recipients simultaneously without burdening individual devices. This type of communication is primarily used in streaming and synchronization networks.

Range: 224.0.0.0 – 239.255.255.255

Broadcast IP Addresses

Broadcast addresses are designed for communication with all devices within the same subnet. They are useful for distributing data, such as updates or commands.

Example: For the network 192.168.1.0/24, the broadcast address is 192.168.1.255.

Anycast IP Addresses

Anycast addresses are shared among multiple devices, with traffic directed to the nearest available device according to routing rules.

Usage: DNS servers, content delivery networks (CDN).

IPv6 and Its Specific Addresses

IPv6, the successor to IPv4, provides a much larger address space and introduces several new types of addresses.

• Link-local addresses: FE80::/10, for communication within a local network.

• Unique local addresses: FC00::/7, similar to IPv4 private addresses.

• Multicast addresses: FF00::/8.

• Loopback address: ::1 (equivalent to IPv4 127.0.0.1).

• Global addresses: Publicly accessible addresses, equivalent to IPv4 public addresses.

Understanding the various types of IP addresses and their ranges is crucial for proper network configuration, infrastructure scaling, and security. Whether you are configuring a home Wi-Fi network or managing a corporate data center, knowledge of IP addressing will simplify your tasks and improve your network's functionality.