The networking of computers is nearly as old as computing itself. It’s roots can be traced back as far as 1961 when the idea of ARPANET was proposed Leonard Kleinrock. Since that time there have been a series of gradual improvements to the ideas and technologies.
Significant points in the timeline can be shown as
1965 when the term packet was used to describe data been sent between computers on a network
1969 the Internet was officially born
1973 Ethernet is developed
1974 first Routers are used. However, these Routers are not considered to be true IP Routers
1976 development of the first IP Router
1978 the invention of the TCP/IP protocol
1983 implementation of the first DNS
1988 details of the first firewall are published
1990 the first network switch is developed and introduced
A computer network is a collection of computing nodes connected in a number of ways that allow them to communicate with each other. The network comprises Routers, Hubs, Bridges, and Switches.
In order the ensure interoperability between computers on a network, standards must be defined and adhered to. The most important one is the OSI 7 layer model. It is a reference model that specifies standards for communications protocols and also the functionalities of each of the 7 layers.
Computers communicate with each other using predefined protocols. A protocol is the set of rules that define the way how two entities can communicate across the network. It would specify patterns of communication and data structures. Each layer of the OSI 7 layer models is governed by 1 or more protocols, such as TCP, IP, UDP, ARP, DHCP, FTP, and so on.
In order for computers to be able to identify each other on a network, they need an identifier. There are several types of identifiers used in the network.
Hostname
A unique device name (names can clash) on the network
Open a command prompt and type hostname
IP Address (Logical Address)
The IP Address is the network address of the system across the network. Notice we say the system here and not the device. More on this later. It is assigned to the system when it is bootstrapped, and it can be changed at any time whilst the system is actively running.
To identify each device in the world-wide-web, the Internet Assigned Numbers Authority (IANA) assigns an IPV4 (Version 4) address as a unique identifier to each device on the Internet. There are more devices in the world than there are IP addresses, so addresses are distributed based on organizational requirements.
The length of the address is 32-bits for IPv4, giving us an available 232 IP addresses. Or 128-bits for IPv6 giving us an available 2128 IP addresses.
From the command type - ipconfig
MAC Address (Media Access Control) - Physical Address
The MAC Address is the unique identifier of each node and is associated with its NIC (Network Interface Card). A MAC address is assigned to the NIC at the time of manufacturing. It can not be changed.
The length of the MAC address is : 12-nibbles == 6 bytes == 48 bits
A nibble is 4-bits