Computer Networks Basics (Part 2)

IP Address:

     An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network. IP address serves two purposes, host or network interface identification and location addressing. Internet Protocol version 4 (IPv4) defines an IP address as a 32-bit number and new version of IP (IPv6), uses 128 bits for the IP address.

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Types of IP Address:

1. Private IP Address: 

        A private IP address is a non-Internet facing IP address. Private IP addresses are provided by network devices, such as routers, using network address translation (NAT).

2. Public IP Address:

        A public IP address is an IP address that can be accessed over the Internet. The public IP address is a globally unique IP address assigned to a computing device.

Versions of IP Address: 

1. IPv4:

        Internet Protocol Version 4 is the fourth revision of the Internet Protocol used to identify devices on a network. IPv4 is the most widely deployed Internet protocol used to connect devices to the Internet. IPv4 uses a 32-bit address scheme allowing a total of 2^32 addresses. Ex: 192.168.4.23

2. IPv6:

        Internet Protocol Version 6 is the newest version of the Internet Protocol reviewed in the IETF standards committees to replace the current version of IPv4. IPv6 addresses are 128-bit IP address written in hexadecimal and separated by colons. An example IPv6 address could be written like this 3ffe:1900:4545:3:200: f8ff: fe21:67cf.

IP Address Classes:

     There are five classes of IP addresses, they are Class A, Class B, Class C, Class D and Class E, where only A, B, and C are commonly used.

 

Subnetwork (Subnet):

     A subnet is a logical subdivision of an IP network. Dividing a network into two or more networks is known as subnetting. Computers that belong to a subnet are addressed with a significant bit-group in their IP addresses. Subnetting results in the logical division of an IP address into two parts, the network address, and the host identifier.

Super network (Supernet):

     Supernet is an Internet Protocol network that is formed, for combining two or more networks into a larger network. The benefits of supernetting are conservation of address space, gaining efficiency regarding memory storage and route information processing.

Network Address Translation (NAT):

     Network address translation (NAT) is a method of remapping one IP address space into another by modifying network address information in IP header packets while they are in transit. It has become a popular and essential tool in conserving global address space in the face of IPv4 address exhaustion.

Dynamic Host Configuration Protocol (DHCP):

     The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on UDP/IP networks. A DHCP server dynamically assigns an IP address and other network configuration parameters to each device on a network so that they can communicate with other IP networks.

TCP:

     TCP stands for Transmission Control Protocol, which is a widely used protocol for data transmission over a network. TCP establishes a connection between two hosts before transmitting data, to ensure that data transmitted over the network reaches the destination without fail. TCP also known as a connection-oriented protocol, establishes a reliable connection between sender and receiver. TCP provides error and flow control mechanisms which help in orderly transmission of data and retransmission of lost packets.

UDP:

     UDP stands for User Datagram Protocol, which is connectionless protocol, mostly used for connections that can tolerate data loss. UDP is used by applications on the internet that offer voice and video communications, which can suffer some data loss without adversely affecting the quality. UDP does not provide error and flow control mechanisms because of which it does not require a connection to be established before transmitting data over the network.

ICMP:

     ICMP stands for Internet Control Message Protocol; this is widely used for internet communication troubleshooting or generated in response to errors in IP operations, this will send packets to the target machine and will see whether the packets are delivered or not.

Address Resolution Protocol (ARP):

     Address Resolution Protocol (ARP) is a communication protocol used for discovering the link layer address, such as a MAC address, associated with a given network layer address. This mapping is a critical function in the Internet Protocol suite. It works within the boundaries of a single network never routed across inter-networking nodes. ARP uses a simple message format containing one address resolution request or response. The size of the ARP message depends on the link layer and network layer address sizes.

Domain Name System (DNS):

     Domain Name System (DNS) is a naming system for resources connected to the Internet or a private network. The DNS is responsible for assigning domain names and mapping those names to Internet resources by designating name servers for each domain. Network administrators have authority over the subdomains of their allocated namespace to other name servers. Domain Name System is an essential component of Internet functionality.

Internet Group Management Protocol (IGMP):

     Internet Group Management Protocol (IGMP) is a communication protocol used by hosts and adjacent routers on IPv4 networks to establish multicast group memberships. IGMP is an integral part of IP multicast. IGMP can be used for one-to-many networking applications such as online video streaming and gaming and allows the more efficient use of resources.

Routing:

     Routing is the process of selecting a path for traffic in a network or across multiple networks. In routing, network packets from their source toward their destination are routed through intermediate network nodes by specific packet forwarding mechanisms. Intermediate nodes are typically networked hardware devices such as routers, bridges, gateways, firewalls, or switches. In routing, process packets are directed on based on routing tables, which maintain a record of the routes to various network destinations. An administrator specifies the routing table.

Routing protocol:

     Routing protocol specifies how routers communicate with each other, distributing information, which enables them to select routes between any two nodes on a computer network. Routing algorithms determine to choose a specific route. A routing protocol shares this information first among immediate neighbors, and then throughout the network. The major types of routing protocols.

• Routing Information Protocols (RIP).
• Interior Gateway Routing Protocol (IGRP).
• Open Shortest Path First (OSPF).
• Exterior Gateway Protocol (EGP).
• Enhanced Interior Gateway Routing Protocol (EIGRP).
• Border Gateway Protocol (BGP).
• Intermediate System-to-Intermediate System (IS-IS).

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