Circuit switching - message exchange - packet switching - virtual circuit and packet data
IP datagrams - Format - fragment
Routing and Routing Protocols Overview
IP address classification (A Class B Class C Class D E class)
Network Address Translation (NAT)
Calculation and subnet mask subnetting
ARP protocol
DHCP protocol
ICMP protocol
IPv6
RIP to OSPF and BGP protocol agreement
IP Multicast and Mobile IP
Network layer summary: https://www.bilibili.com/video/BV19E411D78Q?p=60