1.3 Networks & Protocols

1.3 Networks & Protocols

1. Types of Networks

   • LAN: Small geographical area, has your own hardware.
   • WAN: Large geographical area, has 3rd party hardware. Eg. internet
   • Client to server: Central server that connects everything, security is central backup. Is expensive and difficult to maintain. If central server is down, everything is down.
   • Peer to Peer: All computers are connected and on equal access levels, everything is done by the computers, nothing else goes offline if one computer goes offline.

2. DNS (Domain Name Server)

   • 1. URL is sent to DNS
   • 2. Looks for the IP address
   • 3.. Sends IP back to the computer
   • 4. If IP is not found, IP is sent out to next DNS, or an error
   • DNSs are spread out across the planet to find IP addresses

3. Topologies & Hardware

   • Star Topolgy: everything is connected to the server. If the switch goes, everything goes. Usually more expensive.
   • Mesh Topology: No single point of error, everything is connected to one another.
   • WAP: Connects to Wireless Network
   • Router: Sends and receives data
   • NIC: Allows you to access a network Wired or Wireless.
   • Transmission media: Ethernet (cables), Fibre Optic (cables using light, fastest), Wireless (WiFi, can be intercepted).

4. Protocols

   • HTTP(S): HTTP allows you to access websites, HTTPS is the same but encrypts the data / makes it more secure
   • FTP: Allows to access files from the server
   • SMTP: Sends an Email from one server to another server.
   • POP(3): Downloads Emails, then removes them from the server
   • IMAP: Downloads Emails, and keeps on server
   • TCP/IP: Breaks down into packets, then sends the data

5. IP vs MAC & Others

   • IP Addresses can be Static and Dynamic, while MAC Addresses only static (meaning their value stays the same for the device no matter what).
   • IP Addresses are either 32-bit or 128-bit (depending on if they are IPv4 or IPv6), using either just numbers or hexadecimal as well (again dependant on IPv4 or IPv6), while MAC Addresses are 48-bit, using hexadecimal.
   • IP is used by routers to forward data packets across networks, while MAC is used by switches to forward data within a local network.
   • Bandwidth: The amount of data that can pass between a network of devices per second.

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