(1) Part 1– What is computer network?
(2) Part 2– Computer network topology
(3) Part 3– What is the Fiber optic cable?
(4) Part 4– What is an internet?
Friends, in this part we are discussing what is an internet, here are the main points of this topic
The internet is an international extensive size network that interacts with computer devices all over the universe.
Types of Internet connection
Cellular Network– A cellular network or mobile network is a connection network that the end link is wireless. The network is shared by ground zones called “cells”, all served by at least one fixed-location transceiver, but generally, three cell sites or support detection device locations.
These device locations bring the cell along with the network support that might be practiced for the transfer of voice, information, and various kinds of content.
A cell generally practices a separate set of frequencies from neighboring cells, to reject attachment and bring assured performance character among every cell.
Broadband- Broadband is not a committed connection between our assumptions and the local network. It is variable bandwidth, asymmetric, effect quicker for downloads than for uploads, and subject to competition among others.
A leased line is a committed connection between our assumptions and the local network. It is limited bandwidth and attempts matching upload and download speeds and is not likely to compete among other end users.
Leased Line– A leased line is a personal telecommunications program among multiple areas granted just as a commercial agreement.
It is further defined as a personal program and such information line in the UK. Generally, leased lines are operated by businesses to communicate geographically remote workstations.
Organizations of Internet
IANA- IANA represents the Internet Assigned Numbers Authority. It is recognized management which inspects universal IP address segment, self-ruling structure number segment, bottom area management in the domain name structure, media types, and various internet contract-related logos and internet numbers.
ARIN- ARIN stands for the American Registry for Internet Numbers. It is the regional internet registry for Canada, the United States, and the many Caribbean and North Atlantic Islands. ARIN controls the sharing of internet number properties, consisting of IPv4 and IPv6 address space and AS numbers.
ICANN– ICANN stands for the Internet Corporation for Assigned Names and Numbers. It is an American multi-stakeholder group and nonprofit organization responsible for coordinating the maintenance and procedures of Most the databases linked to the namespaces and numerical spaces of the Internet, protecting the networks reliable and durable process.
IEEE– IEEE represents the Institute of Electrical and Electronics Engineers. It is expert management for electronic engineering and electrical engineering with its corporate work station in New York City and its working center in Piscataway, New Jersey.
IETF– IETF stands for the Internet Engineering Task Force. It is authorized management, that progress and advertises spontaneous internet authorizations, in appropriate the models which contain the internet agreement group. Not accept formal membership roster or membership needs.
What is Intranet?
Friends, we know about the Internet but now we will discuss Intranet. An intranet is a computer network for sharing information, association appliances, working devices, and various computing services interior of management, continuously to the rejection of connection by strangers.
What is ARPANET?
ARPANET represents an acronym for Advanced Research Projects Agency Network. It was the first wide-area packet switching network with distributed control and one of the first networks to implement the TCP/IP protocol suite. Both technologies became the technical foundation of the internet.
Founding– From 1966, Advanced research project.
Operator– From 1975, Defense Communications.
Protocols– 1822 protocol, NCP, TCP/IP
Closed– 1990
MILNET– In computer networking, MILNET was the name confirmed to the unit of the ARPANET internetwork nominated for ordinary United States Department of Defense traffic. MILNET was visually differentiated from the ARPANET in 1983.
WAN networking- The key WAN protocols that are in use are Asynchronous Transfer Mode(ATM), Broadband Access, frame Relay, Point-to-point protocol(PPP), Synchronous, and optical network(SONET), Synchronous Digital Hierarchy(SDH), X, 25, and some other WAN protocols.
What is DNS?
DNS represents Domain Name Server. DNS is that the identity of a phone book. They manage a directory of domain names and alter them to Internet Protocol (IP) addresses.
This might be essential because domain names are simple for people to recognize, computers are digital structures, connect websites supported IP addresses.
What is the MAC address?
MAC stands for Media Access Control. MAC address could be a unique identifier assigned to a network interface controller to be practiced as a network address in communications within a network segment.
This utilize is normal in the highest IEEE 802 networking technologies, consisting of Ethernet, Wi-Fi, and Bluetooth.
MAC address– D4-BE-D9-8D-46-9A.
Wireless Media of computer networking
Wireless media/network is a technology that connects networking devices using radiofrequency. So we can connect all networking devices wirelessly.
But it covers a small area in comparison to wired technology. We can use this technology over a small area like home, small office, schools for wireless communication.
Wireless transmission waves
Radio Waves
It is an Omni-directional antenna, frequencies between 3KHz and 1GHz. It uses for multicast or multi-way communications, such as radio and television, and paging systems. These waves can penetrate buildings easily so that widely used for indoor and outdoor communication.
Radio waves Antenna – An Antenna is a structure that is generally a metallic object that may be a wire or group of wires, used to convert high-frequency current into electromagnetic waves.
Transmission Antenna– It transmits radio frequency from the transmitter, then convert to electromagnetic energy by Antenna and then, radiate into the surrounding environment.
Microwaves
Microwaves are perfect when huge regions need to be covered and there are no issues in the pathway.
Microwaves Transmission- Microwaves are unidirectional, their electromagnetic waves having frequencies between 1GHz and 300GHz. They are mostly used for one-to-one communication between the sender and receiver.
Example- Cellular phone, satellite networks, and in wireless LANs(wifi), Wimax, GPS.
There are two types of microwaves data communication system- (a) Terrestrial (b) Satellite
Infrared
Infrared frequencies between 300 GHz to 400THZ. It mostly uses for short-range communication. Example- Night vision camera, Remote control, File sharing between two phones, communication between a PC and peripheral device. (Bluetooth, wifi, etc)`
How does the wireless network work?
Wi-Fi
Wi-Fi stands for Wireless Fidelity. It is a trademark of the Wi-Fi alliance. The category title for materials utilizing the IEEE 802.11 connection of values. It is mainly utilized for Wireless Local Area Network(WLAN).
It has two types of card – (a) Internal (b) External
Wi-Fi standards
Year released
IEEE Standard
Frequency
Maximum data rate
1999
1999
2003
2009
2014
2019
802.11a
802.11b
802.11g
802.11n
802.11ac
802.11ax
5GHZ
2.4GHz
2.4GHz
2.4GHz and 5GHz
2.4 GHz and 5GHz
2.4 GHz and 5GHz
54Mbps
11Mbps
54Mbps
600Mbps
1.3Gbps
10-12Gbps
Bluetooth
It is a wireless Personal Area Networks(WPAN). It is a low cost, low power, small size, mobile use. IEEE 802.15.1 family of standards. It has two types of card – (a) Internal (b) External
Year introduced
Bluetooth version
Feature
2004
2007
2009
2010
2013
2014
2016
2.0
2.1
3.0
4.0
4.1
4.2
5.0
Enhanced data rate
Secure simple pairing
High speed with 802.11 Wi-Fi radio
Low-energy protocol
Indirect IoT device connection
IPv6 protocol for direct internet connection.
4X range, 2x speed, 8x message capacity+ IoT.
Differences between Bluetooth and Wi-Fi
Bluetooth
Wi-Fi
(1) Specifications authority – Bluetooth SIG
(2) Year of development – 1994
(3) Bandwidth – Low(800kbps)
(4) Hardware requirements – Bluetooth adaptor on every system accessing among them.
(5) Cost – Low
(6) Power consumption – Low
(7) Frequency – 2.4 GHz
(8) Security – less secure
(9) Range – 10 meters
(10) Primary devices – Mobile phones, mice, keyboards, office, and industrial automation devices.
(11) Ease for use – Fairly simple to use. It can be used to connect up to 7 devices at the same time. It is simple to control within devices or identify and link to any device.
(1) Specifications authority – IEEE, WECA
(2) Year of development – 1991
(3) Bandwidth – High (11Mbps)
(4) Hardware requirements – Wireless adaptor on each system of the network, a wireless router, and/or connecting ports.
(5) Cost – High
(6) Power consumption – High
(7) Frequency – 2.4 GHz
(8) Security – More secure
(9) Range – 100 meters
(10) Primary devices – Notebook computers, desktop computers, servers.
(11) Ease of use – It is more complex and requires the configuration of hardware and software.
Types of wireless security
Open wireless network– Open wi-fi networks has no security. We should not set up an open wi-fi network. It is risky.
WEP 64– Lack of security and it is the old WEP protocol standard is untrusted, that’s why we might not go for it.
WEP 128– This is WEP but with a larger symbol key size. It isn’t absolutely any less accessible than WEP 64.
WPA2-PSK(TKIP)– This uses the advanced WPA2 standard with an older TKIP device. This isn’t safe and is only a good idea if you have older devices that may not link to a WPA2-PSK(AES) network.
WPA2-PSK(AES)– This is the highest security system. It utilizes WPA2, the advanced wi-fi symbol standard, and the modernized AES system protocol. On many devices, we will just see the option “WPA2” OR “WPA2-PSK”. If we do, it will probably just use AES, as that’s a common-sense choice. We may utilize this security system.
WPAWPA2-PSK(TKIP/AES)– Different devices push forward and even recommend this mixed-mode option. This purpose provides both WPA and WPA2, with both TKIP and AES.
This provides the highest ability with any former devices we might have, but also provides an attacker to break our network by cracking the more unprotected WPA and TKIP protocols.
Advantages and disadvantages of wireless network
Advantages
Disadvantages
(1) It has the freedom to work and access networks from anywhere.
(2) No cable required, saves cable cost.
(3) Quick and easy to install
(4) Easily expandable according to our requirements.
(5) Mobile friendly
(1) High cost.
(2) Slower than wired network
(3) More risk
(4) Less transferring data
(5) Shorter range
Protocols
It is a set of rules for a particular object. Networking technology using various types of protocols to manage the network and share information from one network device to another network device.
Protocol types
IP– IP stands for internet protocols and it is used to connect one pc to others.
TCP– TCP stands for transmission control protocol and this protocol allows pc to share data with reliability, security, slow, and also manage the packets. And TCP provides acknowledgment.
UDP– UDP stands for Used datagram protocol. This protocol allows pc to carry the data fast, unreliable, insecure, and UDP doesn’t provide any types of acknowledgment and it is used for video streaming also.
ARP– ARP stands for Address Resolution Protocol. It is used to find Mac addresses from IP addresses. ARP works on switch devices.
RARP– RARP stands for Reverse Address Resolution protocol. It is used to find an IP address from Mac address and work oppo…of ARP
DNS– DNS Stand for domain name system. It is used to find the IP address to find the IP to name like XYZ.com=10.0.0.10
DHCP– DHCP stands for dynamic host configuration protocol and it is used to manage IP over a network. It provides dynamic IP or auto IP over a network.
POP– POP stands for post office protocols this protocol is used to receive the email.
IMAP– Stand for internet message access protocol. It means that all of your emails are saved on your internet service provider’s servers. If we are using IMAP, We can run an email program at home and an email program at work and both programs will access the same setup messages and folders.
SMTP– SMTP stands for simple mail transfer protocol. Used to send email messages.
FTP- FTP stands for File Transfer protocol. It used to upload and download.
HTTP– HTTP stands for, HyperText Transfer Protocol. It uses to access web data.
HTTPS – HTTPS stands for, HyperText Transfer Protocol over Secure socket layer. It used to a highly sensitive online agreement like online banking and online shopping order forms.
NTP– NTP stands for Network Time protocol. It used to manage network router and server time to sync the time.
Difference between TCP and UDP
TCP
UDP
(1) TCP is a connection-oriented protocol. Connection-orientation means that the cooperating devices should assemble a network before transferring data and should close the network after transferring the data.
(2) TCP is reliable as it guarantees the delivery of data to the destination router.
(3) TCP provides an extensive error checking mechanism. It is that it supports flow control and approval of data.
(4) Arranging data is a character of transmission control protocol(TCP). This system that post arrives properly at the target.
(5) Retransmission of lost packets is possible in TCP, but not in UDP.
(6) TCP does not support Broadcasting.
(7) TCP is relatively less speed than UDP.
(1) UDP is the Datagram-oriented protocol. This is because there is no overhead for opening a connection and terminating a connection. UDP is reliable for broadcast and multicast kind of computer network data transfer.
(2) The delivery of information to the targeting point should not be trustworthy in UDP.
(3) UDP has a single important error checking mechanism using checksums.
(4) In UDP there is no arrangement of files. If an order is required, it has to be managed by the application layer.
(5) UDP is faster, simpler, and more efficient than TCP.
(6) There is no retransfer of erasing packets in user Datagram Protocol(UDP).
(7) UDP supports Broadcasting.
IP addresses
Internet protocol and assign on the computer for computer identity. It is a unique address it may be decimal or hexadecimal an internet protocol the address is an arithmetic type assigned to every single element linked to a computer network that uses the internet protocol for transmission.
It has two types of categories
(1) Network Id (2) Host ID
IP version 4(TCP/IPV4) address is 202.56.215.200 or 10.0.0.0, 10.0.0.100, 172.168.0.25
IP version 6(TCP/IPV6) address is 2001:0db8:85a3:0000:0000:8a2e:0370:7334
Difference between IPV4 and IPV6
IPV4
An IP address a 32bit address that uniquely universally defines the connection of a host or a router to the internet. An IP address is unique.
Introduced by IANA(INTERNET Assigned Numbers Authority). 32 bit is shared into 4 equivalent units of 8-8 bits differentiated by dotted statistic documentation.
It is in the range of a minimum of 0.0.0.0 to 255.255.255.255. Each 8-bit group is known by OCTET.
IPV6
An IP address fundamentally a 128-bit location that especially globally describes the connection of a host or a router to the internet. The IP address is unique.
It introduced by IANA(Internet Assigned Numbers Authority). A total of 4,294,967,296 unique IP addresses can be assigned to hosts.
This IP is like 2001:db8:1234::f350:2256:f3dd/64. It supports Unicast, Telecast, and Multicast. It doesn’t have classes like IPV4.
Classes of IP addresses
Class A– It ranges from 1 to 126 Decimal value in the first Octet. And the first Octet defines the network part and the remaining three octet defines the Host part. It structures similar to this NHHH(N-Network, H-HOST, H, H).
The First 8bits define the network and the remaining 24bits define host parts. It has the highest nos of addresses which are about 16,277,216. Lie between 10.1.1.1 to 126.255.255.255.
Class B– This IP ranges from 128 to 191 Decimal value in the first octet. And first two-bit defines the network part and the remaining two-octet defines the host part. It patterns like NNHH(N-NETWORK, N, H-HOST, H).
The First 16bits define the network and the remaining 16 bits define host parts. It has the highest nos. of addresses which are about 65,536. IP starting range from 128.16.0.0 to 172.31.255.255.
Class C– This IP ranges from 192 to 223 Decimal value in the first octet. And first 3bits define the network part and the remaining one octet defines the Host part. It patterns like this NNNH(N-Network, H-Host).
The First 24bits define the network and the remaining 8 bits define host parts. It has the highest nos. of addresses which are about 53,68,70,912. IP ranges from 192.168.0.0 to 223.255.255.0.
Class D– This IP ranges from 224 to 239 Decimal value in the first octet. It is not usually used in general applications. It is used in special-purpose applications are known as Multicast.
Class E– This IP ranges from 240 to 255 Decimal value in the first octet. It is not usually used in general applications. It is a reserved range of IP by R and D (Research and Development) department. Usually, Class A to C is supported by PC, and class D, class E is not supported.
Subnet mask
A subnet mask is a 32 or 128-bit number that segments an existing IP address in TCP/IP network. It is utilization by the TCP/IP protocol to transform in case a the host is on the local subnet or a remote network.
Subnet mask divides the IP address into a network address and host address, to identify which part of the IP address is reserved for the network and which part is accessible for host use.
How to identify a class of IP address
Class
Range
Subnet musk
A
B
C
D
E
1-126
128-191
192-223
224-239
240-255
255.0.0.0
255.255.0.0
255.255.255.0
What is DHCP?
DHCP stands for Dynamic Host Configuration Protocol. A DHCP could be a network server that automatically provides and assigns IP addresses, default gateways, and other network parameters to client devices. It relies on the quality protocol to respond to broadcast queries by clients.
IOT
The Internet of assets instructs the network of material items-“things”- that are fixed with sensors, software, and other technologies for the purpose of linking and switching data with other devices over the web.
Vulnerability
Vulnerability Existence of a weakness, design, or implementation error that may result in an unexpected event compromising the safety of the system. We can check our vulnerability by install some software or tools. We are able to install NMAP, ZENMAP, WIRE SHARK, etc.
How to secure our network?
(1) We must always not provide private IP to all public
(2) Don’t share devices with public
(3) Create server lab
(4) We must always avoid communication with unknown network
(5) Use device password and admin authentication.
(6) Use a firewall for incoming and outgoing connection
(7) Restrict internet access.
(8) We will use a monitor tool to test our network.
(9) We are able to use the PRTG server for monitoring our network. These are the points that how can we secure our network.
What is ping?
PING stands for Pocket Internet Grapher. PING command is sometimes used as an easy way to verify that a computer can communicate over the network with another computer or network device. The PING command operates by sending Internet Control Message Protocol(ICMP) Echo request messages to the destination computer and anticipating a response.
What are the network Threads?
Macro Viruses – Most common kind of virus on campus affect Microsoft office documents written in visual basic for applications. It’s generally harmless with some destructive variants.
Executable viruses – It’s the foremost common kind of virus on campus. Written in programming languages and compiled into executable files.
Backdoor programs – We should always not allow anyone on the web, it can cause and infect our computer. It comes from proxy mail, proxy website, click the proxy link, etc. Its activities are like effect send and receive files, can view the screen, they can monitor all keystrokes.
Types of cyber attacks
Malware – Stand for Malicious software. It’s ransomware, designed to damage or control a computer system.
Phishing – Fake office emails(bank, PayPal) link to fake websites, where victims log in, giving up their passwords.
Middle attacks – Hackers insert themselves between our computer and therefore the web server.
DDOS – Stand for Distributed Denial of Service. It’s a network of computers that overloads a server with data, shutting it down.
Cross-site scripting – It injects malicious code into a website that targets the visitor’s browser.
SQL injection attack – It corrupts data to create a server divulge data, like MasterCard numbers, usernames.
What is computer network Firewall
A firewall is a security point of the device which is used to filter the packet for incoming and outgoing connection and protect our infrastructure. It’s either hardware or software-based, which monitors all incoming and outgoing traffic, and supported an outlined set of security rules it accepts, rejects or drops that specific traffic.
Accept- Allow the traffic.
Reject– Block the traffic but reply with an unreachable error.
Drop– Block the traffic with no reply.
A firewall establishes a barrier between secured internal networks and outdoors untrusted networks, like the internet.
There are two types of firewalls.
(A) Software-based firewall – It is built-in technology in all os. and users can configure it using the control panel.
(B) Hardware-based firewall– It’s safer and reliable for network security. It is very costly. It has more feature and user can monitor network devices and create port security. Also can configure and control the port and access permission over a network.
What is a proxy server?
It is a server that executes as a connection for requirement from clients searching resources from other servers. Most of the proxies are web proxies that accelerate permission to content on the web while giving privacy.
Troubleshooting
We can check out the network on a computer if these problems are showing-
(a) No internet connection – (1) Check ports and adapters (2) Check Physical connectivity like a router, wires, and switch. (3) Check default in cable line (4) Restart network devices and systems.
(b) No printing – (1) Check printer spooler service. (2) Restart it (3) Go to services.msc. (4) Now give the printing command.
(c) Pinging problem – (1) Check host and Medium (2) Check Firewall (3) Check discovery (4) Check IP address.
(d) IP conflict – (1) If it is pinging then change IP (2) Check with ping in another device after shutdown. (3) Go to ncpa.Cpl and select adapter and IPv4 or IPv6. (4) Now give a new unique supported static IP.
So friends, in this part we have discussed the key points I really wanted to point out to you as far as what is computer network and its types. This topic I hope all 4 parts were helpful for all, if it was helpful please share this blog. If You have any questions about this topic go ahead and leave them in the comment section and I will answer it For you, I want to thank you for taking the time to read this topic.
