Networks & Basic Concepts Flashcards
The “5 9’s” Rule
Availability of networks is expected to be 99.999% of the time. (5 minutes of downtime per year)
Network Components: Client
Device end-user accesses the network with
Any device that connects to the network
Network Components: Server
Provides resources to the rest of the network
Different servers = Different functions
Can be dedicated hardware/software or a device that is acting like a server for a particular function
Network Components: Hub
Older tech to connect networked devices
Receives information in one port and rebroadcasts to all ports
Network Components: Switch
Connects networked devices such as clients/servers.
Learn which devices are on which ports
Only forward traffic to destination port based on MAC
More security, efficiently uses bandwidth
Network Components: Router
Connects two different networks together
Intelligently forwards traffic to/from a network based on its logical address
Most routers use IP to determine routing
Network Components: Media
Connect two devices or a device to a port
Copper, fiber optic, WiFi (radio frequency)
Network Components: WAN Link
Physically connects networks together
Examples: DSL, Cable, FIOS, Satellite, Cellular, Microwave
Connects internal networks to external networks
Network Resources: Client/Server Model
Uses dedicated server to provide access to files, scanners, printers, & other resources
Administration & backup are easier since resources are on a few key servers
Network Resources: Client/Server Benefits
Centralized administration
Easier management
Better scalability
Network Resources: Client/Server Drawbacks
Higher cost
Requires dedicated resources
Requires network operating system
Network Resources: Peer-to-Peer Model
Peers share resources with each other directly
Administration & backup are more difficult since resources are spread across many PCs
Network Resources: Peer-to-Peer Benefits
Lower cost
No dedicated resources required
No specialized OS required
Network Resources: Peer-to-Peer Drawbacks
Decentralized management
Inefficient for large networks
Poor scalability
Network Geography: PAN
Personal Area Network
Smallest type of wires/wireless network
Covers least amount of area (few meters)
Bluetooth/USB to laptop/Firewire camera to computer
Network Geography: LAN
Local Area Network
Connects components in limited distance
Each segment is limited to short distances (CAT5 = 100m)
Internal wired/wireless cards
Network Geography: CAN
Campus Area Network
Connects building-centric LANs across a university, industrial park, or business park
Covers many square miles/buildings
College campus, business parks, military bases
Network Geography: MAN
Metropolitan Area Network
Connects scattered locations across a city
Larger than CAN, but smaller than WAN
Up to 25-mile radius in larger cities
City departments (police), Community college with campuses spread across a county
Network Geography: WAN
Wide Area Network
Connects geographically disparate internal networks
Leased lines or VPNs tunneled over the Internet
Covers distances around the country/world
Internet, connecting two private corporate networks
