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DNS
in simple words you can say that DNS is like a library which have list of ip address and corresponding names
The Domain Name System is how our computers translate our regular,
everyday text into network readable IP addresses. When you type codenody.com into
your browser address bar and hit enter, your computer contacts its DNS server. The
DNS server responds with the corresponding IP address of makeuseof.com, connects,
and brings you up glorious technology content for your enjoyment.
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UDP
UDP stands for user datagram protocol. It is a popular companion protocol to TCP and is also implemented in the transport layer.
The fundamental difference between UDP and TCP is that UDP offers unreliable data transfer. It does not verify that data has been received on the other end of the connection. This might sound like a bad thing, and for many purposes, it is. However, it is also extremely important for some functions.
Because it is not required to wait for confirmation that the data was received and forced to resend data, UDP is much faster than TCP. It does not establish a connection with the remote host, it simply fires off the data to that host and doesn't care if it is accepted or not.
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MAC ADDRESS
it stands for media access control.
it is the address which uniquely identifies the device in the network
Media access control is one of the only protocols from the link layer that you are likely to interact with on a regular basis.
MAC address is 48 bit in length
MAC addresses are also known as hardware addresses or physical addresses. They uniquely identify an adapter on a LAN.
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SWITCH
The switch is used to connect different devices in a network.Hub and switch both perform same functionality but switch do not broadcast the packets,it determines the address of the receiver and only sends the packet to that device.switch do not waste bandwidth for this reason switch is preferred more over a hub.
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BRIDGE
A device used to connect two separate Ethernet networks into one extended Ethernet. Bridges only forward packets between networks that are destined for the other network. It operates on the second
layer of the OSI model.
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MODEM
MODEM
it stands for Modulator and Demodulator. A modem is a device that allows a system to send and receive data over a cable or satellite connection. The main function of the modem is to convert information from digital mode from the analog mode and vice versa.
Modem are of different types
- Half duplex
- Full duplex
- Synchronous Modem
- Asynchronous Modem
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ROUTER
a router is a device which is used to connect multiple computer networks with the help of wired or wireless connections. The router is a layer 3 device it operates on the network layer.A router acts as a default gateway .it calculates the best path to reach network destination.components of a router are
CPU, flash memory, ram, network interfaces, console.
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HUB
Hub is a used to connect computers or other devices in a network. Hub broadcast the information to all the connected devices to its ports. Hubs do not store any information about devices connected to it.
they were very popular in past because of they are cheaper. A switch is different than a hub in that it keeps a record of all MAC addresses of all connected devices. Thus, it knows which device or system is connected to which port.
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ICMP
Its stands for internet control message protocol.
ICMP is required for the smooth functioning of the ip(internet protocol).
Icmp transfers control information for the status of the network.
When user do ping then icmp is used
Icmp sends message to the source ip address when network problem prevents
The delivery of the packet.
Icmp is not a transport protocol. icmp is used by network administrators to troubleshoot internet connections
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IP address
It stands for internet address. Every device connected over the network have an unique ip address. This number uniquely identifies the hardware device on the network.it is used for the communication between the system.its like an address to device.
An ip address look like this
220.227.144.146
Ip address consists lots of information about your network ,device itself in its body.
There are different type of ip addresses
There are different type of ip addresses
Public ip- Private ip
- Dynamic
- Static ip
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Port
Port are end point of communication in a system. As we know computer system offers many services. each service has a port number. Specific port numbers are reserved for specific services. These ports allow user to access particular service.
On physical context,
Ports are present on system which provide a way to give and receive output from a system.
- Ethernet ports
- USB ports
- Serial ports
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PROTOCOL
Generally, it is defined as the set if rules that governs communication on the network. A specific set of communication rules are called protocols.
We have different protocols for different purposes TCP/IP,SSH,SOAP HTTP etc.
http- hyper text transfer protocol is the most common used protocol.it is used to transmit data over the web.
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Packets
Packet is defined as the container which holds data and travel over the network.
Everything you see on a network is coming in the form of a packet.
For example – email, this webpage.
Each packet carries the information that will help it to reach destination.
A packet contains 1000 or 1500 bytes.
Packets are also known by other names
- Frame
- Block
- Cell
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FIREWALL
Firewall protects our network from malicious websites and hackers.It provides network security by filtering the incomming
and outgoing requests .firewall works under set of defind rules.
there are three types of firewalls
there are three types of firewalls
- Packet Filtering
- Application layer firewall
- stateful firewall
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TCP/IP PROTOCOLS
Port numbers range from 0 to 65536, but only port numbers 0 to 1024 are reserved for privileged services and designated as well-known ports.
List of tcp and udp protocol numbers
| Protocol | Port number |
|---|---|
| FTP | 20/21 |
| Telnet | 23 |
| SMTP | 25 |
| DHCP | 67/68 |
| HTTP | 80 |
| HTTPS | 443 |
| ONS | 53 |
| SQL SERVER | 156 |
| SSH | 22 |
| SQL SERVICES | 118 |
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VPN(Virtual private network)
VPN allow users to securely access a private network and share data remotely through public networks.
VPN protects our data online.these are used to secure sensitive data when connecting remote data centers .VPN allows you to hide your IP informationa
and encrypt your connection to prevent it from hackers.with VPN you can access websites which afrre forbidden in certain countries.
reason of slow speed of internet after connecting to vpn
VPN has four basic protocols.each protocol has various encryption levels.the higher level of encryption leads to the lower the speed of the internet
reason of slow speed of internet after connecting to vpn
- While using VPN ,your internet speed depends upon distance you have between your location and location of vpn serverfind server location near to your country.
- free vpn load,this happens with free vpn servers because many users are connected to it at same time.
- firewall settings also affect your connection speed
- data-packet loss
VPN has four basic protocols.each protocol has various encryption levels.the higher level of encryption leads to the lower the speed of the internet
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NAT(Network address translation)
it is the process where an etwork device, usually a firewall assigns a public ip address to a computer.
the main use of NAT is to limit the number of public IP address an company must use both for economy and security purpose.
with the help of NAT ,only single unique IP is required to represent an entire group of computers. shortage of IP addresses is the only one reason to use NAT.
with the help of NAT ,only single unique IP is required to represent an entire group of computers. shortage of IP addresses is the only one reason to use NAT.
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Cryptography
it is used to protect valueable information and resources .Cryptography provides secure communicaion.
Encryption uses an algorithum and a key to transform an input into an encrypted output.
Cryptography is of two types
Cryptography is of two types
- Symmetric cryptography -both encoder and decoder uses same keys to perform their operations
- Asymmetric cryptography -encoder and decoder uses different keys to perform their operations
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DHCP(Dynamic host configuration protocol)
it is a protocol which helps in configuring IP to host dynamically.it assigns IP address to the machine
.one network can have more then two DHCP servers dhcp server have a pool of ip address which have range of ip address dhcp server can assign
host system make a request to dhcp server for ip address, then dhcp response to host.
There are four main functions of a DHCP server
when use vpn service dynamic host configuration protocol works there.
There are four main functions of a DHCP server
- DHCP discovery
- DHCP offer
- DHCP request
- DHCP acknowledgement
when use vpn service dynamic host configuration protocol works there.
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IPV4 V/S IPV6
| IPV4 | IPV6 |
|---|---|
| IPV4 are 32 bit in length | IPV6 are 128 bit in length |
| IPV4 lacks in security | IPV6 has strong security |
| IPV4 header has 20 bytes | IPV6 header has 40 bytes |
| Packet Fragmentation done by both Router and sending host | Packet Fragmentation done only both by sending host |
More information will be avilable from next update