TLDR - IP Address
An IP address, short for Internet Protocol address, is a unique numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. It serves two main purposes: identifying the host or network interface and providing the location of the device in the network.
Structure of an IP Address
An IP address is a 32-bit number divided into four octets, separated by periods. Each octet represents a decimal value ranging from 0 to 255. For example, an IP address could be represented as 192.168.0.1. The IP address is divided into two parts: the network address and the host address. The network address identifies the network to which the device is connected, while the host address identifies the specific device within that network.
Types of IP Addresses
There are two main types of IP addresses: IPv4 and IPv6.
IPv4, or Internet Protocol version 4, is the most widely used IP addressing scheme. It uses a 32-bit address space, allowing for approximately 4.3 billion unique addresses. However, due to the rapid growth of the internet, IPv4 addresses are becoming scarce.
IPv6, or Internet Protocol version 6, was developed to address the limitations of IPv4. It uses a 128-bit address space, providing an almost unlimited number of unique addresses. IPv6 adoption is gradually increasing to accommodate the growing number of devices connected to the internet.
Dynamic and Static IP Addresses
IP addresses can be classified as dynamic or static.
Dynamic IP Addresses
Dynamic IP addresses are assigned to devices by a Dynamic Host Configuration Protocol (DHCP) server. These addresses are temporary and can change each time a device connects to the network. Dynamic IP addresses are commonly used by internet service providers (ISPs) to efficiently manage their address space.
Static IP Addresses
Static IP addresses are manually assigned to devices and remain constant over time. They are typically used for devices that require a permanent address, such as servers or network printers. Static IP addresses are less common and often come at an additional cost.
Public and Private IP Addresses
IP addresses can also be categorized as public or private.
Public IP Addresses
Public IP addresses are globally unique and can be accessed from the internet. They are assigned by ISPs and are used to identify devices on the public internet. Public IP addresses are necessary for devices that need to communicate with other devices outside of their local network.
Private IP Addresses
Private IP addresses are used within private networks and are not accessible from the public internet. They are reserved for internal use and allow devices within a local network to communicate with each other. Private IP addresses are defined by specific ranges, such as 192.168.0.0 to 192.168.255.255, and are not routable on the internet.
IP Address Allocation
The allocation of IP addresses is managed by regional internet registries (RIRs) and internet service providers (ISPs).
RIRs are responsible for the distribution and registration of IP addresses within specific regions. They allocate blocks of IP addresses to ISPs, who then assign them to their customers.
ISPs are the entities that provide internet connectivity to end-users. They receive blocks of IP addresses from RIRs and assign them to their customers based on their needs.
IP addresses are essential for identifying and locating devices on computer networks. They come in different types, such as IPv4 and IPv6, and can be dynamic or static, public or private. Understanding IP addresses is crucial for network administrators, internet service providers, and anyone working with computer networks.