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Networking Fundamentals

Beginning

The first iteration of the Internet was within the ARPANET project in the late 1960s. This project was funded by the United States Defence Department and was the first documented network in action. However, it wasn't until 1989 when the Internet as we know it was invented by Tim Berners-Lee by the creation of the World Wide Web (WWW). It wasn't until this point that the Internet wasn't used as a repository for storing and sharing information (like it is today).

Research

Tim Berners-Lee: [WIP]

ARPANET: [WIP]

IP Addresses

Set of numbers divided into four octets: 192.168.1.1

Protocols:

IPv4: 2^32 ( 4.29 billion IPs) - 86.157.52.21

IPv6: 2^128 (340 trillion-plus IPs) - 2001:0db8:85a3:0000:0000:8a2e:0370:7334

MAC Addresses:

Media Access Control address is assigned by the factory to a physical network interface when it was built.

It is a twelve-character hexadecimal number: a4:c3:f0:85:ac:2d

Ping (ICMP):

Network tool that allows us to determine the performance of a connection between devices:

LAN:

Local Area Network

Subnetting:

Subnetting is the term given to splitting up a network into smaller, miniature networks within itself. [WIP]

ARP Protocol:

Address Resolution Protocol [WIP]

DHCP Protocol:

Dynamic Host Configuration Protocol [WIP]

OSI:

Open System Interconnection Layers:

  1. Application

  2. Presentation

  3. Session

  4. Transport

  5. Network

  6. Data Link

  7. Physical

Packets & Frames

Rule:

When we talk about IP Addresses, we talk about Packets. When we do not talk about IP Addresses, we talk about Frames.

Packet Headers:

TTL | Checksum | Source Address | Destination Address

Ports 101

Numerical value between: 0-65535

Most common ports:

  • Web: HTTP (80) - HTTPS (443)

  • FTP: 21

  • SSH: 22

  • SMB: 445

  • RDP: 3389

Full list of common (1024 common ports): http://www.vmaxx.net/techinfo/ports.htm

Firewall

[WIP]

Snort: https://www.snort.org/

VPN

[WIP]

DNS

command to get DNS Records of a website:

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