MAC
MAC Addresses are unique 48-bits hardware number of a computer, which is embedded into network card (known as Network Interface Card) during the time of manufacturing. MAC Address is also known as Physical Address of a network device. A MAC address is a hardware identification number that uniquely identifies each device on a network. MAC addresses are made up of six two-digit hexadecimal numbers, separated by colons. For example, an Ethernet card may have a MAC address of 00:0d:83:b1:c0:8e. every hexadecimal characters represents 4 bits, so the first six hexadecimal characters represent the manufacturer’s or vendor’s number.
IP addresses
An IP address is a unique address of each device(computer or any other network device) connected to a network. It is a series of four numbers each ranging from 0 to 255 separated by dots or periods. (e.g 192.168.1.1). This address may change every time the computer restarts. A computer can have one IP address at one instance of time and another IP at some different time. IP addresses are written in dotted decimal form but computer internally covert them into binary form. For example : an IP address in dotted decimal form : 216.27.61.137 and same address in binary form is 11011000.00011011.00111101.10001001
IPv4 Address(Internet Protocol Version 4)
An IPv4 address is a 32 bit addressing scheme and has following format : x.x.x.x, where x is called an octet and must be a decimal value between 0 to 255. Octets are separated by periods. An IPv4 address must contain three periods and four octets.
IPv6 Address(Internet Protocol Version 6)
The IPv6 format was created to enable the trillions of new IP addresses required to connect not only an ever-greater number of computing devices but also the rapidly expanding numbers of items with embedded connectivity. In the Internet of Things (IoT) scenario, objects, animals and people are provided with unique identifiers and the ability to automatically transfer data over a network without requiring human-to-human or human-to-computer interaction. IPv6 expands the available address space sufficiently to enable anything conceivable to have an IP address. An IPv6 address is a 128 bit addressing scheme and can have either of the following formats:
(i) Normal( Pure IPv6 format)
(ii) Dual(IPv6 plus IPv4 formats).
Normal
It has following format y:y:y:y:y:y:y:y where y is a segment and can have any hexadecimal value between 0 and FFFF. The segments are separated by colons. It nust have 8 segments.
Dual
It combines IPv6 and IPv4 address and has following format : y:y:y:y:y:y:x.x.x.x
Domain Name System
It is the system which assigns names to some computers(web servers) and maiantains a database of these names and corresponding IP addresses, which known as Domain Name Reslution. The URL of the website is known as its domain name. The domain name is unique name of a website. A domain name generally contains following parts: (i) www (ii) name describing the website’s purpose (iii) TLD( top level domain) such as .com, .net, .org, .edu, .in etc. Examples of some domain are www.amazon.com, www.wayn.com.cn, www.dce.edu, www.cbse.nic.in etc.
Web address(URL)
A location on a net server is called a website. Each site has a unique address called URL( Uniform Resource Locator) e.g. the website of Microsoft has an address or URL called http://www.microsoft.com. URL defines four things: Protocols, Host Computer, Port, and Path. The basic format of URLs is type://address/path where type specifies the type of server in which file is located, address is the address of server, and path tells the location of the file on the server. For example http://www.CBSE.nic.in/academics.html is a URL for a specific website. In this URL first part http stands for a protocol, and the second part indicates the IP address or domain name where the source is located, and academics.html specifies the name of the specified html document on a website of CBSE.
Routing
The router is responsible for the routing of traffic between networks. Routing is the process of moving data packets between different networks. By default two computers cannot communicate with each other. They need a mediator device that can switch packets between them. Router takes this responsibility.
Routing tables
Routers use Routing Tables to determine out which interface the packet will be sent. A routing table lists all networks for which routes are known. Each router’s routing table is unique and stored in the RAM of the device. A routing table is a set of rules, often viewed in table format, that is used to determine where data packets traveling over an Internet Protocol (IP) network will be directed.
