EN-Ethical Hacking_module_Basic_networking.pdf

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1. Testing & Ethical
Hacking& Ethical
Hacking
Basic of Networking

2. OSI Models
The OSI (Open Systems Interconnection) model defines
networking functionality

4. Physical Layer (Layer 1)
Function: Ensures network node connectivity through
wired or wireless means.
Common Attacks:
Sniffing Attack:Gaining physical access to intercept
data.
Physical Damage: Harming cables or devices to disrupt
services

5. Data Link Layer (Layer 2)
Function: Manages communication between connected
network nodes and breaks data into frames for
transmission..
Common Attacks:
MAC Spoofing: Altering MAC addresses to masquerade
as another device.
ARP Spoofing: Associating an attacker's MAC with
another IP.

6. Network Layer (Layer 3)
Function: Responsible for packet forwarding, including
routing through routers.
Common Attacks:
IP Spoofing: Creating IP packets with a false source
address.
Routing Attacks: Manipulating routing tables with false
information.
Man-in-the-Middle (MITM) Attack
Denial-of-Service (DoS): Overwhelming the network
with traffic.

7. Transport Layer (Layer 4)
Function: Provides transparent transfer of data and
ensures complete data transfer.
Common Attacks:
SYN Flood: Exhausting server resources during TCP
handshake.
UDP Flood: Overwhelming target with UDP packets.

8. TCP Connection

9. TCP Flags
•URG–UrgentFlag
•ACK–AcknowledgeFlag
•PSH–PushFlag
•RST–ResetFlag
•SYN–SyncFlag
•FIN–FinishFlag

10. Session Layer (Layer 5)
Function: Manages communication sessions, ensuring
efficient data transfer and closing sessions upon
completion
Common Attacks:
Session Hijacking: Stealing a valid session.

11. Presentation Layer (Layer 6)
Function: Translates data between application layer and
network format, performs encryption/decryption.
Common Attacks:
SSL Stripping: Downgrading HTTPS to HTTP.
Phishing Attack: Attackers use deceptive techniques
(e.g., fake emails or websites) to trick users into disclosing
sensitive information or installing malicious software.

12. Application Layer (Layer 7)
Function: Interfaces directly with user applications to
facilitate communication
Common Attacks:
SQL Injection: Manipulating or destroying databases.
Cross-Site Scripting (XSS): Injecting malicious scripts.

13. OSI Layers

14. An identifierfor a computer or device on a TCP/IP
network.
The format of an IP address is a 32-bit numeric
address written as four numbers separated by
periods.
Each number can be zero to 255. For example,
1.160.10.240 could be an IP address.
IP Addressing (IPv4)

15. IPv4
255 255 255 255
Network Host
•ClassA:
•ClassB:
•ClassC:
•ClassD:
•ClassE:
Network Host Host Host
8bits8bits 8bits8bits
Multicast
Research
NetworkNetwork Host Host
NetworkNetworkNetwork Host

16. IPv4
ClassA:
Bits:
Host Host
1617 2425 32
Range(1-127)–16,777,214hosts
1 89
Bits:
1617 2425 32
ClassB:
10NNNNNN Network Host Host
Range(128-191)–65,534hosts
ClassC:
Bits:
Network Host
1 89
110NNNNN Network
1617 2425 32
Range(192-223)–254hosts
1 89
Bits:
ClassD:
1110MMMM MulticastGroupMulticastGroupMulticastGroup
1617 2425 32
Range(224-239)
0NNNNNNN

17. 127.0.0.0
Network number that cannot be assigned to any
network
127.0.0.1
The loopback address
Used for diagnostic testing of the local TCP/IP
installation
Loopback address

18. Port
A port number is a way to
identify a specific process
to which an internet or
other network message is
to be forwarded when it
arrives at aserver.