Summary Networking Essentials Sum

Chapter 1: Explore the network
Network has no boundary and supports the way we:

- Learn
- Communicate
- Work
- Play

Client request and display information

Servers provide information to other devices on the network

Computer can be both server and client at the same time

Peer-to-peer

Advantages:

 Easy to set up
 Less complexity
 Lower cost since network devices and dedicated servers may not be required
 Can be used for simple tasks such as transferring files and sharing printers

Disadvantages:

 No centralized administration
 Not as secure
 Not scalable
 All devices may act as both clients and servers which can slow their performance

Components of network

3 categories of network components:

 Devices
o End devices
 Either the source or destination of a message
 Computer, laptop, …
o Intermediary network devices
 Connect multiple individual networks to form an internetwork
 Connect the individual end devices to the network
 Ensure data flows across the network
 Provide connectivity
 Examples:
 Network access devices (switches; wireless access points)
 Internetworking devices (routers)
 Security devices (firewalls)
 Media
o Network media
 Provide the pathway for data transmission
 Interconnect devices
 3 types of media: wireless, LAN, WAN
 Services

NIC = network interface card

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,Physical port = a connector or outlet on a networking device

Interface = specialized ports on an internetworking device that connect to individual networks




Topology diagrams

Physical topology diagrams = identify the physical location of intermediary devices, configured ports, and cable
installation

Logical topology diagrams = identify devices, ports, and IP addressing scheme

LAN & WAN

Local Area Networks (LAN): a network infrastructure that provides access to
users and end devices in a small geographical area

 Interconnects end devices in a limited area
 Administrated by a single organization
 Provide high speed bandwidth to internal devices

Wide Area Network (WAN): a network infrastructure that provides access to
other networks over a wide geographical area

 Interconnects LAN
 Administrated by multiple service providers
 Provide slower speed links between LANs

Others:

 Metropolitan Area Network (MAN)
 Wireless LAN (WLAN)
 Storage Area Network (SAN)

Internet, intranet and extranet

Internet = worldwide collection of interconnected networks, not owned by any individual or group

Internet access technologies:

 Internet service provider (ISP)
 Broadband cable
 Broadband digital subscriber line (DSL)
 Wireless WANs
 Mobile services
 Business DSL
 Leased lines
 Metro ethernet
 Kabelmodem


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, o Een special type modem dat wordt gebruikt om data over het kabeltelevisienetwerk (bestaande uit
coax en glasvezel) te transporteren



Types of internet connections: home and small office, business

Snelheid internetconnectie:

 Bandbreedte = de maximale hoeveelheid informatie die van 1 plaats naar een andere plaats over het
netwerk kan stromen in een gegeven tijdsinterval. Deze wordt uitgedrukt in bits per seconde.
 Throughput (werkelijke bandbreedte afhankelijk van aantal gebruikers op het netwerk) = de hoeveelheid
informatie (= data + overhead) die over het netwerk werd doorgestuurd binnen een bepaald tijdsinterval.
 Goodput = meet de werkelijke data-overdracht over een netwerk gedurende een bepaald tijdsinterval

Vertraging = de minimale tijd die een netwerk nodig heeft om de kleinst mogelijke hoeveelheid data te versturen.

Converged networks

traditional separate networks = each network with its own rules

Converging network = capable of delivering data, voice and video over the same network infrastructure

4 basic characteristics of network architecture:

 Fault tolerance
o Redundant connections allow for alternative paths if a device or a link fails. The user experience is
unaffected
 Scalability
o Additional users and whole networks can be connected to the internet without degrading
performance for existing users
 Quality of service (QoS)
o All communication has some access to the media, but higher priority communication has a greater
percentage of the packets
 Security
o Administrators can protect the network with software and hardware security and by preventing
physical access to network devices




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, Networking technologies for the Home

Smart home

Powerline networking = uses existing electrical wiring to connect devices

Wireless broadband:

 wireless internet service provider (WISP)
 wireless broadband service using cellular technology (4G)

Security
Threats examples Solutions examples
Viruses, worms and Trojan horses Antivirus and antispyware
Spyware and adware Firewall filtering
Zero-day attacks (zero-hour attacks) Dedicated firewall systems
Hacker attacks Access control lists (ACL)
Denial of service attacks Intrusion prevention systems (IPS)
Data interception and theft Virtual private networks (VPNs)
Identity theft

Data center = a facility used to house computer systems and associated components including:

 redundant data communications connections
 high-speed virtual servers
 redundant storga systems (typically uses SAN technology)
 redundant or backup power supplies
 environmental controls (air conditioning, fire suppression)
 security devices

data center Google: bekabeling uitgevoerd in Fiber en hebben een warmtenet


Chapter 2: configure a network
operating system
Cisco IOS (Internetworking Operation System)

Network operating system = enables device hardware to function and provide an interface for users to interact.

Kernel = the portion of the operating system that interacts directly with computer hardware

Shell = the portion that interfaces with applications and the user

The user can interact with the shell using a command line interface (CLI, text-based environment) or graphical user
interface (GUI)

CLI is less resource intensive and very stable when compared to a GUI

Operating systems:

 pc open source (OC) allows users to interact with the computer
 user-computer interaction in PC operating systems (OS) are often done via mouse, keyboard and monitor
 cisco IOS = operating system
 cisco IOS allows users to interact with Cisco devices



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