Networking Fundamentals

Ethical Hacking CIS4560

pwd

displays the absolute path of the current working directory

ls -la

list all files in long format

Why do Networks mater in Security

1. Networks are Primary attack Vectors

2. Data travels across untrusted networks

3. Protocols have inherent vulnerabilities

4. Network traffic can be intercepted

Port 80

HTTP | Hyper Text Transfer Protocol; Allows web browsers to send requests to servers and recieve responses

Port 20

FTP data transfer active mode

Port 21

FTP control connectionS

Port 22

SSH | protocol used to establish an encrypted secure connection between two computers

TCP

Transmission Control Protocol; a connection-oriented reliable data transfer

UDP

User Datagram Protocol: fast, connectionless protocol(unreliable)

Security Implications of TCP/IP stack

1. Each layer has potential vulnerbilities
2. Attackers can target any layer
3. Data can be intercepted between layers
4. Protocol weaknesses can be exploited

Port 443

HTTPS(or DNS over HTTPS) | HTTP over SSL(Secure Sockets Layer) and TLS (Transport Layer Security)

Port 53

DNS | Domain Name System - name resolution: translating human-friendly domain names (like nytimes.com) into machine-readable IP addresses

Port 23

Telnet | old network protocol used for remote login and command-line communication with other computers or devices over a network

Port 22

SSH (or SFTP)| Secure Shell, a cryptographic network protocol that enables secure remote access to computers and servers over an unsecured network. Provides a secure channel for communication by encrypting the data exchanged between the client (your local machine) and the server (the remote machine)

Port 3389

RDP | Remote Desktop Protocol

Port 5900

VNC| Virtual Network Computing. 

Port 25

SMTP| Simple Mail Transfer Protocol. Unencrypted and can be weak to email spoofing.

Port 110

POP3| Post Office Protocol v3