Cloud Networking Glossary
Learn the Fundamentals

What is an IP Address?

IP, in IP address, stands for Internet Protocol and the address is a numeric address that is assigned to every single computer, printer, switch, router or any other device connected to the Internet. IP addresses make it possible for Internet-connected devices to communicate with each other. An IP address uniquely identifies devices and provides sender and delivery locations for each of them. When something is sent from a device, the IP address identifies the sender and when something is sent to a device, the IP address directs where it should be delivered.

IP addresses are managed globally by the Internet Assigned Numbers Authority (IANA), which is a function of ICANN, along with five regional Internet registries (RIRs). In each of their designated regions, they are responsible for IP address assignments for end users and local Internet registries, such as Internet service providers.

How IP Addresses Work

IP addresses are composed of a series of numbers. This numeric protocol is divided into two parts – network and host. The network part specifies the network that the IP address belongs to, which can be an ISP or an internal network. The host part identifies the device and pinpoints its location.

The IP address is assigned by the Dynamic Host Configuration Protocol (DHCP), a service running on the network. DHCP typically runs on network hardware, such as routers or dedicated DHCP servers.

When a device is added to a network, a four-step process is used to secure an IP address from the DHCP.

  1. Discover : The device broadcasts a message on the network to find a DHCP provider.
  2. Offer: DCHP providers identify the unique hardware address of the device and offer services to it.
  3. Request : The device selects a DCHP provider, from those available, and sends a request for an IP address assignment.
  4. Acknowledge: The selected DCHP provider acknowledges the request and issues an IP address to the device that is not being used any other devices on the network.

Static and Dynamic IP Addresses

IP addresses can be static or dynamic.

Static IP addresses are configured by a device’s network settings and do not change. Static IP addresses are used for devices that require constant access, such as an FTP server, web server or printer shared over a network.

Dynamic IP addresses are temporarily assigned to a device when it is connected to a network. They are automatically assigned by a DHCP server. Dynamic IP addresses are commonly used by Internet Service Providers and networks with a large number of connected devices. The assignment of dynamic IP addresses is transparent to users except for the rare case where two devices on the network have the same IP address (this is, generally, resolved automatically).

Standards for IP Addresses

The two standards for IP addresses are IP Version 4 (IPv4) and IP Version 6 (IPv6). An IPv4 address consists of four numbers, each of which contains one to three digits separated with a single dot (.) separating each set. An IPv6 address consists of eight groups of four hexadecimal digits.

Explosive growth in mobile devices has nearly overwhelmed the capacity of IPv4 IP addresses, which led to IPv6. IPv4 supports a maximum of 4,294,967,296 unique IP addresses whereas IPv6 was designed to support 340,282,366,920,938,463,463,374, 607,431,768,211,456.

The working standard for the IPv6 protocol was published by the Internet Engineering Task Force (IETF) in 1998. Japan and Korea were acknowledged as having the first public deployments of IPv6 – in 2004. Unlike IPv4, IPv6 has native support for mobile devices with the Mobile IPv6 (MIPv6) protocol.