CCNA Chapter 1

• Every computer on a network is called a host or end device.
• Servers are computers that provide information to end devices.
• Clients are computers that send requests to the servers to retrieve information.
• It is possible to have a device be a client and a server in a Peer-to-Peer Network. This type of network design is only recommended for very small networks.
• An end device is where a message originates from or where it is recieved. Data originates with an end device, flows through the network, and arrives at an end device.
• An intermediary device interconnects end devices. Examples include switches, wireless access points, routers, and firewalls.
• Management of data as it flows through network is also the role of an intermediary device.
• Metal wires, Fiber-optic cable, Wireless transmission are examples of Media Types.
• Network diagrams, often called topology diagrams, use symbols to represent devices within the network.
• Important terms to know include:

  • Network Interface Card (NIC)
  • Physical Port
  • Interface
• Physical topology diagrams illustrate the physical location of intermediary devices and cable installation.
• Logical topology diagrams illustrate devices, ports, and the addressing scheme of the network.
• Common Types of Networks

  • Small Home Networks
  • Small Office/Home Office
  • Medium to Large Networks
  • World Wide Networks
• Two most common types of networks:

  • Local Area Network (LAN)
  • Wide Area Network (WAN)
• A LAN is a network infrastucture that spans a small geographical area. Administered by a single organization or individual. Provide high-speed bandwidth to internal devices.
• A WAN is a network infrastructure that spans a wide geographical are. Typically administered by one or more service providers. Typically provide slower speed links between LANs.
• The Internet is a worldwide collection of interconnected LANs and WANs.
• The following groups were developed to help maintain structure on the internet:

  • IETF - Internet Engineering Task Force
  • ICANN - Internet Corporation Assigned for Names and Numbers
  • IAB - Internet Activities Board
• An Intranet is a private collection of LANs and WANs internal to an organization that is meant to be accessible only to the organizations members or others with authorization.
• An organization might use an Extranet to provide secure access to their network for individuals who work for a different organization that need access to their data on their network.
• Communication is almost important to us as our reliance on air, water, food, and shelter. In today's world, through the use of networks, we are connected like never before.
• Popular services for home users and small offices include broadbrand cable, broadband digital subscriber line (DSL), wireless WANs, and mobile services.
• Organizations need faster connections to support IP phones, video conferencing , and data center storage.
• Corporate business connections may require:

  • higher bandwidth
  • dedicated connections
  • managed services
• Cellular uses a cell phone network to connect to the internet.
• Dedicated Leased Line are reserved circuits within service provider's network that connect distant offices with private voice and/or data networking.
• True or False. Before converged networks, an organization would have been separately cabled for telephone, video, and data. Each of these networks would use different technologies to carry the signal.

  
  

  Each of these technologies would use a different set of rules and standards.

  
  

  True
• Converged data networks carry multiple services on one link including: data, voice, and video.
• Network Architecture refers to the technologies that support the infrastructure that moves data across the network.
• What are the four basic characteristics that the underlying architectures need to address to meet user expectations:

  • Fault Tolerance
  • Scalability
  • Quality of Service (QoS)
  • Security
• A fault tolerant network limits the impact of a failure by limiting the number of affected devices.
• True or False. Multiple paths are required for fault tolerance.

  
  

  True
• Packet switching spilts traffic into packets that are routed over a network.
• A scalable network can expand quickly and easily to support new users and applications without impacting the performance of services to existing users.
• Quality of Service is the primary mechanism used to ensure reliable delivery of content for all users.
• Two main types of network security:

  • Network infrastructure security - physical security of network devices. Preventing unauthorized access to the devices.
  • Information Security - protection of the information of data transmitted over the network.
• Three goals of network security:

  • Confidentiality
  • Integrity
  • Availability
• True or False. The role of the network must adjust and continually transform in order to be able to keep up with new technologies and end-user devices as they constantly come to the market.

  True
• Several new networking trends that effect organizations and consumers:

  • Bring Your Own Device (BOYD)
  • Online collaboration
  • Video communications
  • Cloud computing
• Bring Your Own Device (BYOD) allows users to use their own devices giving them more opportunities and greater flexibility.