Chapter 1

OSI Reference

Physical link

medium • 1 min read

Data link layer

medium • 2 min read

Network layer

medium • 3 min read

Transport layer

medium • 4 min read

Application

medium • 5 min read

Chapter 2

IP Layer

IPv4 subnet

medium • 1 min read

IPv6 header

medium • 2 min read

ICMP ARP

medium • 3 min read

NAT DHCP

medium • 4 min read

Routing OSPF

medium • 5 min read

Chapter 3

Transport

TCP handshake

medium • 1 min read

UDP datagram

medium • 2 min read

Window sliding

medium • 3 min read

Congestion CTRL

medium • 4 min read

Port numbers

medium • 5 min read

Chapter 4

Application

HTTP DNS

medium • 1 min read

SMTP FTP

medium • 2 min read

Telnet SSH

medium • 3 min read

SNMP tel

medium • 4 min read

Web sockets

medium • 5 min read

Chapter 5

Security

DES RSA crypto

medium • 1 min read

Digital sign

medium • 2 min read

SSL TLS cert

medium • 3 min read

Firewalls IDS

medium • 4 min read

IPSec VPN

medium • 5 min read