Notes1:1FirstDayReview - echadbourne/NET-330 GitHub Wiki
Sending a Letter vs Sending a Packet
| Letter | Packet |
|---|---|
| Look up recipient address - Phone Book | DNS - Domain Name Service |
| Put in addressed envelope | Add "headers" to data (encapsulate) |
| Put letter in mailbox | Send packet to Network Interface Controller (NIC) |
| Mail carrier picks up letter and takes it to local post office | Send packet to the Default Gateway (LAN router) |
| Post office sorts and sends to next PO facility | Router sends packet to next router |
| How does PO know where to send next? - Use "routing lists" | Use "routing table" of IP networks |
| Ends up at local PO of recipient | Ends up at local router of recipient |
| Mail carrier delivers to recipient using street address | Router and switches send to recipient using host part of IP and MAC address (ARP for MAC address) |
- grandma - mailbox
- aol.com - domain (email server - translates to an IP address)
aol.com would be an mx (mail exchange) record in this case
OSI Model
- Open Systems Interconnection (OSI) is a network protocol framework that uses 7 layers
- The 7 layers define the different stages that data must go through to travel from one device to another over a network
Please Do No Teach Students Pointless Acronyms - Physical, Data Link, Transport, Session, Presentation, Application (1-7)