Chapter 1 - Intro to Networks

Chapter 1 - Intro to Networks

1. Network?

   • two or more connected computers that can share resources
   • Local Area Network (LAN)?
     • Usually restricted to spanning a particular geographic location. e.g. Office Building, Signel Dept., Corporate office.
     • Workgroups?
       • Big LAN's can be split into small logical zones.
       • Arrange LAN workgroups along department divisions. e.g. Sales, Marketing, Accounting.
     • Used to connect a group of hosts together
   • Wide Area Network (WAN)?
     • Span large geographic locations and employ both routers and public links.
     • Used to connect various LAN's together.
     • MPLS - MultiProtocol Label Switching
       • Pros: Physical layout flexibility, Prioritizing of data, one to many connection.
       • Switching mechanism that imposes lables to data and then uses those lables to forward the data.
   • Peer to Peer
     • No central authority, all peers so when it comes to authority they're all equals. They can be client and servers at the same time.
   • Client Server
     • Single server uses a network operating system to manage the whole network. A server handles security and directs clients to the resources it wants.

2. Common Network Components

   • Workstations
     • Powerful computers, resources are available to there users on the network
   • Servers
     • Powerful computers that run specialized software for the network's maintenance and control.
   • Hosts
     • Broad term that can be used to describe almost any type of networking device. A network device, including workstations and servers, with IP addresses.

3. Network Topologies

   • Physical
     • Gives you the lay of the land
   • Logical
     • Shows how the digital signal navigates the layout.
   • Bus
     • 2 terminated ends, with each of its computer connecting to one unbroken cable running its entire lenth
     • Pros: Easy to install, inexpensive. Cons: Hard to troubleshoot, change, or move, and no fault tolerance.
   • Star
     • Computers are connected to a central point (Hub, Switch, Access Point).
     • Pros: Fault Tolerance, Scaleable, easy to troubleshoot Cons: Installation costs, Single point of failure (Hub, Switch, Access Point)
   • Ring
     • Each Computer is connected directly to other computers in the same network.
     • Pros and Cons same as Bus but it is pricier that Bus.
   • Mesh
     • There is a path from every machine to every other machine. Not usually found in LAN's
     • Pros: Fault tolerance Cons: Pricey, Complicated
   • Point-to-Point
     • Direct connection between two devices creating 1 communication path. From one router to another router.
   • Point-to-Multipoint
     • Succession of connections between an interface and multiple destination interfaces. One router to multiple routers.
   • Hybrid
     • A combination of two or more types of physical or logical network topologies working together within the same network.