Ethical Hacking | Full Networking Topics 2020 Part-2

NETWORKING  

 

👉 Categories Of Wire :-

• Modem / Telephone  ⇒   56 kbps 
• Ring                           ⇒   2 - 4 mbps 
• Ethernet                    ⇒   10 mbps 
• Ring                           ⇒   16 mbps 
• Fast Ethernet            ⇒   100 mbps 
• Giga Ethernet           ⇒   1000 mbps 
• 10 Giga Ethernet      ⇒   5 - 10 gbps 

👉 Cabling :- 

Types of cables are as follows :- 

• Straight 

• Cross 

• Rolled Over  

1) Straight :- It is a cable used between un-similar devices like PC to Hub , PC to Switch ,  Hub/Switch to Router , Hub/Switch to Printer.

2) Cross :- It is a cable used between similar devices like PC to PC , Hub to Hub , Hub to Switch , PC to Router. 

3) Rolled Over :- It is used to configure Switch and Router. We can say console cable. 

👉 Networking Devices :- These are the devices that are mostly heard of like switches , routers , etc.

1. Hubs :- It is a central device which is used to connect two or more systems. It is divided in two parts :-

* Active Hub :- It takes external power and is used to regenerates signal. 

* Passive Hub :-  It doesn't take external power and doesn't regenerate signal.  

• Speed :- 10 mbps 
• Speed divides 
• Half duplex 
• Single collision Domain 
• Minimum used in 4 port 
• Works in Physical Layer of OSI model 

2. Bridges :-  

• It is a central device. 
• It divides network in two segments which require less power.
• It maintains mac table. 
• Half and full duplex. 
• Multi collision domain.
• It works in data link of OSI model. 
• Maximum port limit is 16. 

3. Switches :- 

• It is a central device which is use to  regenerate signal.
• It is divided in two parts Managable switch and Non - managable switch.
• Managable switch can be managed via pc console.
• We can change speed and duplexing.
• We can create V LAN.
• We can create trunk. 
• Speed is 10/100/1000 mbps.
• Half and Full Duplex 
• Multi collision domain 
• Single Broadcast Domain 
• It maintains mac table 
• It performs mac binding   

4. Transreceiver :- 

It is a device which provide communication between two different media.

5. Router :- 

• It provides communication between two different technologies and topologies. 
• Router determines best path for source to destination network.
• It is also known as the gateway of network. 
• It performs packet switching and forwarding function. 
• It works on layer-3.
• It reads Ip address.
• It maintains routing table. 
• It blocks / multiplex and broadcast. 
• It is also known as network layer. 

6. Modem :- 

• It work on layer 1.
• It converts analog system into digital system and digital system into analog system.
• Modulation :- Analog to Digital 
• Demodulation :- Digital to Analog

7. B - Router :- 

It is a combination of bridge and router.

8. Firewall :- 

• Firewall filters unwanted traffic and secure network from unauthorized users and hackers. 
• It comes in hardware and software form.   

👉 Protocols :- It is a set of rules and regulations that manage communication. It tells us how to communicate , whom to communicate and when to communicate.

 

👉 TCP Vs UDP :- 

* TCP ( Transmission Control Protocol ) :-

• It is connection oriented protocol.
• It consists of three way handshake.  
• Delivery of packets is guaranteed. 
• It provides flow control and acknowledgement of data
• It keeps track of lost packet. 
• TCP is slow.
• http , ftp , https

* UDP ( User Datagram Protocol ) :-

• It is connection less protocol.
• It consists of one way handshake or no handshake. 
• Delivery of packets is not guaranteed.
• It doesn't keep track of lost packet.  
• UDP is fast.
• It does not provides flow control and acknowledgement of data.
• Dhcp , Ip, telnet , Ip telephony

✌ The number or address assigned to the protocol is given by IANA ( Internet Assign Number Authority ).

👉 Flags Used In Communication :-

• Synchronization Flag ( SYN ) :- SYN or Synchronization flag is used as the first step in establishing a 3 way handshake. In which both the packets of sender and receiver should contain the flag set.    

• Acknowledgement Flag ( ACK ) :- The ACK or Acknowledgement flag is used to provide acknowledgement of successful receipt of the packet from the destination. The receiver sends acknowledgement as well as synchronization flag that it has received its initial packets.   

• Push Flag ( PSH ) :-  The push flag is somewhat similar to the urgent flag and tell the receiver to process the packets as received instead of buffering them. 

• Finished Flag ( FSH ) :- The Finished flag is used by the sender to tell the receiver that it has sent all the packets and there are no more packets left.  

• Urgent Flag ( URG ) :-  The urgent flag is used to notify the receiver to process the urgent packets before processing all other packets. It notifies the receiver when it has received all the urgent packets.  

• Reset Flag ( RST ) :- The reset flag is sent by the receiver to sender when it receives an unknown packet which it was not expecting to receive. 

• 👉 RIP :- Routing Internet Protocol
• 👉 IGRP :- Interior Gateway Routing Protocol
• 👉 EIGRP :- Enhanced Interior Gateway Routing Protocol
• 👉 OSPF :- Open Shortest Path First 

👉 Protocol Stack / Suite :- Group of protocols that work together to complete communication.

👉 OSI Model :- There are 7 layers of OSI model which are as follows :-

• Physical Layer :- To transmit bit over a medium to provide mechanical and electrical specifications. Devices such as network card , cabling and hub are all physical layer equipments.  

• Data Link Layer :- To organize bit into frames to provide hop to hop delivery over a physical wire. The packaging process is called framing and encapsulation. 

Protocol :- ARP , PPP.

• Network Layer :- To move packets from source to destination network to provide internetworking. 

• Transport Layer :- To provide reliable process to process message delivery and error recovery.

• Session Layer :- The Session is established , maintained and terminated between devices. 

• Presentation Layer :- It translates , encrypts and compress users data. It controls the formatting of users data whether it may be in any format text , audio , video , music.  

• Application Layer :- It allows access to network resources. It provides actual interface between users application and the network. The user directly interface with this layer. 

👊 Recently , our government has added 3 more new layers in OSI model for the advancement in communication and privacy. Those 3 layers are as follows :-    

• User / Individual / Political Layer :- It allows IT administrators to identify users , control internet activity of users connected to the internet. It also generates reports by username. 

• Organizational Layer or Blinders Layer :- This layer is for organizational managers who have already decided, usually with little or no current information to dictate a previously successful network plan.

• Government Layer Or Legal compliance :- This layer is used by Government for Service Oriented Architecture. 

⇉  To practice the Configuration of networking devices and how computers are connected in a network , we use Packet Tracer. 

👉 IDS & IPS :- 

⇒ IDS ( Intrusion Detection System ) :- It is a used to gather information within a computer network regarding the security violating policies to protect the network or system from hackers.

⇒Types :-

• HIDS :- Human Based Intrusion Detection System

• NIDS :- Network Based Intrusion Detection System

⇒ IPS ( Intrusion Prevention System ) :- It prevents the hackers from entering into the system.

⇒ Types :-

• Signature Detection :- It reads and check the signature , log files.

• Protocol Detection :- Except the TCP/IP requests, it blocks all other packets.