Internet Protocol (IP) – IP v4 & IP v6

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Internet Protocol is a protocol for addressing and routing packets across the internet. It is again a connection-less protocol. Since TCP requires a connection between the two devices, it is easy to imagine TCP connections when the two devices are on the same network and can communicate with each other. But when they are on different networks, they cannot communicate with each other directly. Thus this communication between two devices in different networks (i.e. inter-network communication) is done by the IP. Internet Protocol defines how packets on the internet move from a source to a destination. The TCP and IP are together responsible for the internet working seamlessly and are together known as TCP/IP.

IP v4 and IP v6 are different version of the Internet Protocol for IP addressing and thus help in communication between devices in computer networks.

Devices on the internet are addressed by using something called Internet Protocol Address (IP address in short). An IP address is a set of 4 numbers where each number is between 0-255. Internally, an IP address is set of 4 octets (or 4 bytes). All the 4 numbers are written together and separated by a dot, e.g. Such an address is specifically called IP v4 address since this addressing came up in the version 4 of the Internet Protocol. The first two numbers are called Network Identifier (12.0) and the last two are called host identifiers (123.255). Network prefix is same for all devices that connect to the internet through the same connection. Each device on the internet has an IP address and a router knows the IP address of all the devices connected to it.

A problem associated withe the above mentioned IP v4 is that the address space of the IP v4 addresses is less keeping in view how fast technology is growing and internet usage and number of internet-enabled devices is expanding. The primary address space was exhausted in 2011 wherein last blocks of IP addresses were allocated. All the approximately 4 billions IP addresses are not enough to handle the number of devices present on the internet today. Thus IP v6 addresses have come up which provide an almost unlimited number of IP addresses.

The benefits of IP v6 over IP v4 are as follows:

  1. A larger address space – IP v6 enables theoretical usage of 2^128 (i.e. 2 raised to the power 128) IP addresses as compared to 2^32 (i.e. 2 raised to the power 32) in IP v4.
  2. More efficient routing – The sizes of routing tables are reduced in IP v6. Therefore they become faster and efficient. Fragmentation of data is also handled by the source device rather than the router. IPv6 drops the IP checksum and thus the need to calculate the checksum of packet at every step/hop during the transmission of packet is done away with, thus increasing packet processing efficiency.
  3. No more Network Address Translation (NAT) – By elimination of NAT, end-to-end connectivity can be achieved between devices wherein they can communicate directly with each other as compared to communication through NAT.
  4. No private address collisions due to the availability of a large number of IP addresses.
  5. Improved security by using IP Security (IPSec) – This will help in encrypting end-to-end traffic between two devices.
  6. Simplified configuration – Address auto-configuration is an inbuilt feature of IP v6. An IP v6 enabled device can auto-configure itself when it is connected to other IP v6 devices. This way, the DHCP can be dispensed away with.
  7. Directed data flows – IP v6 uses multicasting (i.e. communication from one source device to many destination devices in a network) instead of broadcasting (i.e. communication from one source device to all devices within a network). IP v4 focussed more on broadcasting and thus wasted precious bandwidth as data was sent to even disinterested devices in the network. With IP v6, data can be sent to multiple devices without wasting bandwidth.

For Wikipedia entry on IP v4, click here.

For Wikipedia entry on IP v6, click here.

For Wikipedia entry on IP, click here.

For Wikipedia entry on Internet, click here.

For more posts on Internet, click here.

For more posts in The Cyber Cops project, click here.