Computer networks
A system of two or more connected devices, such as computers, servers etc that can communicate with one another
LAN
Local Area Network
internet
A giant network of interconnected computers
Two parts of the internet
Protocols: TCP/IP, HTTP
Hardware: computer devices, cables, satellites
World Wide Web
Global collection of information that can be accessed using the internet
Server
Computer connected directly to the internet
Has a unique name called IP address
ISP - Internet Service Provider
A company that provides you with access to the internet, acting as a gateway to the internet
Router
Responsible for connecting devices to the internet and directing traffic
IPv4
Each number is 8 bits and can hold a number between 0-255
With 4 numbers, IPv4 address has 32 bits
2^32 = 4.3 billion unique address
IPv6
128 bits = 2^128 unique addresses
Format: 8 groups of 4 hexadecimal digits, separated by colons
Why use domain names
IP addresses are not human friendly
Domain names are text names for computers that are easier to remember
How are domain names organized
Hierarchically
Most general part of the hierarchy is at the end of the name
Break it down cpms-people.ok.ubc.ca
ca - Canadian domain
ubc - University of British Columbia
ok - Okanagan campus
cpms-people - name of server on campus
DNS - Domain name system
Translates the hierarchical, human-readable names into IP addresses
DNS process
First checks cache
Asks its nearest DNS name server
Ask root server
Ask top-level domain server
Ak authoritative name servers
works recursively
MAC address
A unique hardware-based identifier permanently assigned to a network adapter by its manufacturer
How do two computers communicate
TCP/IP is the most common protocol used on networks
Uses 2 addresses to identify devices on a network
Messages are broken into small packets that require assembling later
