The digital age is defined by connectivity. From personal messaging to business communications to international governmental relations, nearly all interactions take place over the World Wide Web. At the heart of this vast network, ensuring smooth and reliable communication, is the Internet Protocol (IP). This article aims to shed light on this fundamental aspect of our digital lives.
What is Internet Protocol (IP)?
In the broadest terms, the Internet Protocol is a set of rules that dictate how data should be sent and received over the Internet. Every device that is connected to the internet has a unique IP address, which acts like a mailing address, facilitating the delivery of packets of data from the source to the intended recipient.
The Internet Protocol is a crucial component of the TCP/IP protocol suite, which stands for Transmission Control Protocol/Internet Protocol. This suite comprises a stack of communication protocols used to connect hosts on the Internet.
IP Versions: IPv4 and IPv6
There are two versions of IP in widespread use today: IP version 4 (IPv4) and IP version 6 (IPv6).
IPv4, the older version, provides about 4.3 billion unique addresses. Given the explosive growth of the Internet and Internet-connected devices, it became clear that IPv4 was not scalable enough to provide unique addresses for all devices needing one. Hence, IPv6 was introduced.
An IPv4 address consists of four numbers separated by periods, with each number ranging from 0 to 255. For example, the IP address for one of Google’s DNS servers is 184.108.40.206.
IPv6 is the most recent version and was developed by the Internet Engineering Task Force (IETF) to deal with the long-anticipated problem of IPv4 address exhaustion. IPv6 uses a 128-bit address, meaning it provides over 340 undecillion unique addresses (that’s 34 followed by 37 zeros!), which is vastly more than the human population and is enough to assign a unique address to each device on the Internet for the foreseeable future.
An IPv6 address, on the other hand, is much longer and consists of eight groups of four hexadecimal digits, separated by colons. An example of an IPv6 address could be 2001:0db8:85a3:0000:0000:8a2e:0370:7334.
How Does IP Work?
IP functions by packaging data into packets or datagrams, then sending these packets individually across the network. The protocol specifies that each packet must have header information, including:
Source IP Address: The IP address of the device sending the packet.
Destination IP Address: The IP address of the intended recipient.
Other Information: Including the sequence number of the packet, the length of the payload (the part of the packet that contains the actual data), and information to help reassemble the packets back into the original message.
The journey of a packet from the source to the destination is typically made via several routers, each of which reads the packet’s destination IP address, then sends the packet along to the next router that it thinks can get the packet closer to the recipient.
Importantly, IP is a connectionless protocol. This means that each packet is treated independently of others, and can take different paths from the source to the destination. It’s up to the higher-level protocols, like TCP, to put them back in the right order and request retransmission of any packets that were lost along the way.
Public and Private IP Addresses
Public IP addresses are visible on the internet and must be unique across the entire web to avoid conflicts. An example of a public IP address could be 220.127.116.11, which is one of the public IP addresses for www.google.com.
Private IP addresses are used within private networks and are not routable on the internet. These addresses can be reused in different networks, which helps conserve the global address space. There are several predefined ranges of IP addresses reserved for private use:
10.0.0.0 to 10.255.255.255
172.16.0.0 to 172.31.255.255
192.168.0.0 to 192.168.255.255
For example, a router may assign your laptop an IP address like 192.168.0.5 in your home network.
fc00::/7 to fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff
An example of a private IPv6 address might be fd12:3456:789a:1::1.
Remember, for a device in a private network to communicate with the internet, it must translate its private IP address into a public one, usually through a router performing Network Address Translation (NAT).
Dynamic and Static IP Addresses
IP addresses can be either static (fixed) or dynamic (changing). Static IP addresses are useful when a device needs to maintain a constant address, such as for hosting a website or a file server. Dynamic IP addresses are assigned by a DHCP (Dynamic Host Configuration Protocol) server, and can change over time, which is suitable for most consumer devices that don’t need a permanent IP address.
The Internet Protocol is a fundamental technology that enables the function of the Internet. It defines how data should be packaged, addressed, transmitted, routed, and received at the destination. Though often unseen by the everyday user, understanding IP is crucial to understanding how the Internet functions at a core level. Despite the intricacies involved in the management and assignment of IP addresses, this foundational technology has stood the test of time and continues to adapt as the Internet evolves.