In order to provide computer to computer communication via Internet, we need a global addressing scheme. Such an addressing is provided by Internet Protocol (IP) at the network layer.
It is a 32-bit address This is called an IP address or logical address. Which is made up of the network ID, plus a unique host ID. This address is typically represented with the decimal value of each octet separated by a period (for example, 192.168.7.27). Every Host and router on the internet has an IP Address. This IP address is unique and no two devices on the Internet can have the same address at the same time.
These numbers are assigned by ISP (Internet Service Provider), and IP address can be used to identify the country or region from which a computer is connecting to the WEB.
“IP Address” is the short way to address the term “Internet Protocol Address” IP Addresses refer to a number scheme or the way of providing a unique number to every computer or device that connected to the internet. VINT CERF “the father of the internet” was considered to play a vital role in creating IP Addresses when he used to work for DARPA. The most important features of an IP Address are:
• Globalized and Standardized.
In simple terms, it can be explained as the personal address of the device that is distinctive and specially created for that device. No two devices on the internet can have the same IP Address. For our convenience, we use the names to find things on the internet like if we need to look for Punjab University Chandigarh on the internet, we merely write www.puchd.in but on the machine end, this address is converted in some numerical address so that we can send data to the right location. These IP Addresses are the part of the NETWORK LAYER of the OSI Model, whose primary function is to navigate data between the source and the destination.
IP Address Needs
An IP Address is the numbers that help our computers, servers, telephones, printers, and sensors to communicate with each other. Without these addresses, we first transfer data manually on some CDs, DVDs, hard disk or some other storage material and then need to transfer to the place of its use. Similarly, if our computers don’t have these unique IP Addresses then won’t be able to send any E-mails, and there only paper letters or memos. The worst part: there won’t be any online shopping or online orders system and we would have to shop through stores personally. Thus we can summaries that without IP Addresses there won’t be any use of the internet to people.
An IP Address performs two primary functions:
• Firstly it identifies or finds the host and its location in the network.
• Secondly, it establishes a bridge to the host for communication.
In other words, if we break the IP Address it consists of three necessary parts:
• Name part: it indicates what we are looking.
• Address part: it tells where to find it.
• Route part: it tells how to reach there.
Evert IP Packet’s header consists of IP Address of the sender and the receiver.
IP Address Versions
An IP Address is just a long string of numbers, but in order makes it easy for people to read it, it was written down especially. The original version of IP Address first introduced in the year 1983 in the ARPANET. The first IP was IPv4 that was commercially used. Earlier internet was not that big sensation, and most of the networks were private and were not accessible to other networks of the world. With time the excessive use of the internet, the addresses available for use for the original internet protocol, i.e., IPv4 was entirely exhausted by the internet users and internet service providers. It estimated that when the world’s population was around 7 billion we had just 4.3 billion IP Address for use. Thus to satisfy the ever-increasing need of IP Addresses, Internet Engineering Task Force (IETF) came up with the new IPv6 in 1995, standardized in 1996. The next generation protocol which had massive address space in comparison to the original IPv4. Although it was under testing till mid of the 2000s and was officially came into use in the year 1999, but by 2006 it became successful enough that no more test required on it. At present both IPv4 and IPv6 are in use, and both are entirely different from each other regarding providing addresses. Both will be discussed in detail below.
The First Version IPv4 is the most widely used Internet Protocol. IPv4 addresses are written in the form of a string which consists of 4 numbers with a 3 digit section which lies between the ranges of 0-255. Each number separated by a dot. Each section can be represented in binary form with each section having 8 bits. An IP Address can be written in any form, i.e., binary, octal, and hexadecimal if required. The IPv4 is of size 32-bit storage of maximum that means we can store at max (232) addresses. IPv4 has around 4 billion unique IP addresses. Even out of these addresses some addresses are kept reserved for exclusive use under the category of Private Networks and Multicasting Addresses. A typical IPv4 address looks like as follows:
IP Address: 192.168.90.1
Binary notation: 11000000 . 10101000 . 01011010 . 00000001
IPv4 Address Classes
IPv4 class is a way of division of addresses in the IPv4 based routing. Separate IP classes are used for different types of networks. They can be explained as follows
Class A 184.108.40.206 to 127.255.255.255
Class B 220.127.116.11 to 18.104.22.168
Class C 192.0.0.0 to 22.214.171.124
Class D 126.96.36.199 to 188.8.131.52
Class E 240.0.0.0 to 255.255.255.255
a Router has more than one IP address because router connects two or more different networks. But A computer or host can only have one and a unique ip address. A routers function is to inspect incoming packet and determine whether it belongs to local network or to a Remote Network, if a local packet is determined then there is no need of routing and if a Remote packet is determined then it will route that packet according to the routing table other wise the packet will be discarded.
In the virtual hosting environment, a single machine can act like multiple machines (with multiple domain names and IP addresses.
IP address format
• The 32-bit IP address is grouped eight bits at a time, separated by dots and represented in decimal format. This is known as dotted decimal notation as shown in fig.
• Each bit in the octet has a binary weight (128,64,32, 16,8,4,2, 1).
• The minimum value for an octet is 0, and the maximum value for an octet is 255.
IPv6 Addresses were written using hexadecimal so that they can fit more information using lesser digits. The typical IPv6 address was a long string of numbers in comparison to IPv4. IPv6 uses 128 binary bits to create a single address; the IP address expressed by 8 groups of hexadecimal numbers. Here we used a colon instead of dots to separate the sections of digits. Here if we find 2 colon side by side, that means that all sections between them contain only 0’s. Let’s see the example of address with and without colons below:
With double colon -> 2001:0db7::54
Without double colon -> 2001:0db7:0000:0000:0000:0000:0000:0054
Subnetting refers to the concept of dividing the single vast network into more than one smaller logical sub-networks called as subnets. Sub net is related to IP Address as it borrows a bit from the host part of the IP Address. Thus the IP Address has three parts:
• Network part. (Higher order bits)
• Subnet part.
• Host part. (Remaining bits)
The subnet is formed by taking the last bit from the network component of the IP address and used to specify the number of subnets required. Subnetting allows having various sub-networks within the big network without having a new network number through IPS. Subnetting reduces network traffic and complexity. The purpose of introducing the concept of Subnetting was to fulfill the shortage of IP Addresses. The Subnetting process helps in dividing the class A, class B, and class C network numbers into smaller parts. A subnet can further be broken down into smaller networks known as sub-subnets.
IP address Assignment
An IP Address is provided to us by our ISP, i.e., internet service provider. This address can be of two types:
1. Static Address.
2. Dynamic Address.
If we need to set up a web server or an email service, then we need to use a Static IP Address. Whereas if we want to surf the internet, we need a Dynamic IP Address.
Static IP Address
A static address is also known as a fixed address which means the system with static address have the same address when it is connected over the internet too. These addresses are excellent in terms for those who perform activities related to web hosting, games, voice over internet protocol, etc., These addresses are generally used by persons using commercial lease lines or the public organizations who need same IP address every time.
• Address never change.
• Easy to maintain.
• Ideal for online gaming.
• Speedy and reliable.
• Less down-time.
• Remote access facility.
• Static IP address needs to be configured manually.
• Add to administrative overhead.
• More often there are IP address conflicts.
• Security threats.
Dynamic IP Address
The dynamic internet protocol address or in short dynamic IP address is a temporary address assigned to our computing device when it connected to the network, the dynamic address automatically assigned by our IPS. Every time our computer or router reboot the IPS assigns a Dynamic IP address to our networking device using DHCP protocol. We can check whether we are using a Dynamic IP address or Static IP address by just checking, what the status of DHCP is. If DHCP enables set to YES, that means we are using a Dynamic Address, and if the DHCP enable set to NO, then that means we are using a Static Address. The dynamic address is assigned using Dynamic Host Configuration Protocol (DHCP) that the part of the TCP/IP Suite. The address assigned by the DHCP has an expiration period after which the address can be given to some other device if required, thus helping devices to share limited address space on the network.
• Cost effective.
• Easier to setup and administer.
• Any no. of devices can be connected within internal network with internet access to all devices.
• More privacy with changing IP address.
• Requires Dynamic Host configuration Protocol (DHCP) to obtain IP address.
• No remote access facility.
Type of IP Addresses
There are two types of IP addresses:
Public IP Address
The public IP address is the unique address given to all computers attached to the network. No two machines on the network can have the same IP address. Using these addresses machines can exchange information between each other and can communicate with one another over the network. The user has no control over the Public IP address as it is provided to him by the ISP whenever the machine connected to the internet. A public address can be of any nature, i.e., static or dynamic. It depends upon the need and requirements of the user. Mostly the users have the dynamic type of Public IP address.
Private IP Address
The organizations (IANA) that distribute the IP addresses for use have kept a range of addresses as private addresses for the private network. Private addresses are the addresses that are used by private networks like home or office networks. Here the logic is that these addresses are used within single administration and not on the global network or the internet. The range of addresses set aside for private networks is as follows:
• 192.168.0.0 - 192.168.255.255 (total 65,536 IP addresses)
• 172.16.0.0 - 172.31.255.255 (total 1,048,576 IP addresses)
• 10.0.0.0 - 10.255.255.255 (total 16,777,216 IP addresses)
The device within a private network cannot be connected to the internet directly. If the computer within private network can connect to internet or another network, then that means those computers have both a public IP address as well as a private IP address private IP address to communicate within the network and public IP address to communicate over the internet. If we want to communicate with another private network, then this could be achieved by using a router or a similar device like Network Address Translation (NAT). We can see our computer’s private IP address by using the command ipconfig IPV4 Address on the window command prompt. Mostly the private IP addresses are of Static nature.
IP Address Name Resolution: Domain Name vs. IP Address
An IP address is a logical address that is used to find a particular link on the network. This IP address is generally in the form of numbers as in IPv6 we use complex hexadecimal notions for an IP address. To connect to some network service or even a local network we need an IP address ever time but remembering the long, tedious numbers is not an easy task. As its human nature that we tend to remember names more easily the numbers that why we use Domain names which act as an ALIAS. A domain address is a user-friendly textual address which can be converted into its respective IP address by using a Domain Name System server (DNS). The best example is that of our phone book where the name of the person is a domain name and its phone number is the IP address.