Chapter 6: Networking Fundamentals Flashcards
Why are stand-alone PCs inferior from networked PCs?
Small hard-drive capacities
To print you must have a printer attached locally
Sharing files with other PCs is difficult.
Electronic communication of any sort is impossible.
Network
Links two or more computers together to communicate and share resources.
LAN
Local Area Network
Connect computers in a single office or building.
WAN
Wide Area Network
Expands a LAN to include networks outside of the local environemtn. Allows users to distribute resources across long distances.
Often thought of as multiple, disbursed LANs, networked together.
PAN
Personal Area Network
Small-scalle network designed around a single person.
Usually referrs to networks that use Bluethooth to communicate, like a bluethooth earpiece and a phone.
MAN
Metropolitian Area Network
A network that spans a large geographic distance but is connected using LAN-style architecture, not a WAN.
Best to think of this in terms of its utility – The Googleplex or a large University campus can’t possibley operate with a single LAN. Multiple LANs are built up around the campus and connected to each other, creating a MAN.
The first PC LAN technology was called ____, introduced in the ’80s by Novell
ShareNet
The largest WAN in the world
The Internet
Bluetooth SIG
Bluetooth Special Interest Group
Consortium of companies that participate in developing Bluetooth standards to unit disparate tech industries to allow communication among different devices.
How did Bluetooth get its name?
Named for Harald Blatand (Harold Bluetooth in English) who united several factions in areas of Norway, Sweeden, and Denmark.
Membership of the Bluetooth SIG includes
Microsoft
Intel
Apple
IBM
Toshiba
and several cell phone manufactuerers
Technical Specification that describes a WPAN (wireless personal area network) based on Bluetooth
IEEE 802.15.1
A Bluetooth WPAN is _____ in nature, which makes it unique among other network architectures
Temporary and decentralized
You don’t need a central device to connect. Two devices that are close enough will start communicating.
Piconet
The dynamically created Bluetooth network created when two or more devices are within range of each other.
Maximum number of devices in a piconet
7
Scatternet
One or more devices connect two piconets.
Wireless hotspots, spread throughout a city but connected with the same network infrastructure is an example of a
MAN
What’s the primary difference between a WAN and a MAN?
It’s implied that WANs use publically available communication lines (Telephone network, fiber network of an ISP, etc) to connect.
MANs connect using communication lines owned by the same entity that owns the endpoints that are connected by those lines.
Three primary network components
Servers
Clients / Workstations
Resources
Dedicated Server
Assigned to provide specific applications or services for the network, and nothing else.
Specializes in a single task, like a file server or a print server.
Nondedicated Servers
Assigned to provide one or more network service and/or local access for a user.
Example: Direct network traffic, serve files, and serve as a front-end for the network administrator to manage the network.
Workstations
Computers on which network users do their work.
Everyday computers connected to a network that offers additional resources.
NIC
Network Interface Card
Expansion cad that allows the PC to connect to a network.
What differentiates a server from a workstation
While some would expect this to be hardware, form factor, and whether or not the equipment is rack-mounted, this boils down to:
What role it plays on the network
Network Resource
Any item that can be used on a network.
This can include printers, disk storage, file access, applications
NOS
Network Operating System
Controls the communication with resources and the flow of data across the network.
Examples: UNIX, Linux, and MS’s Windows Server
Peer-to-peer network
Computers act as both service providers and service reqeuestors with each other.
What companies would operate well with a peer-to-peer network?
Small businesses that expect to remain small, do not require a great deal of security.
Client-Server Resource Model
As opposed to peer-to-peer, a client/server model centralizes administrative control and functions from one or more dedicated servers
Name this network model.
Peer-to-peer
Name this network model:
Client / Server
Client/Server-based networks, where security is centrally administored, are known as ____
Domains
When you log into a domain, the login you use is sent to the ______ to determine what network resources to give you access to.
Domain Controller
How do peer-to-peer networks, which do not have domain controllers, determine who has access to what network resources?
On a peer-to-peer network, individual PCs on the network determine whether a user on a different workstation can access files on that PC.
Name the five primary network topologies
Bus
Star
Ring
Mesh
Hybrid
Name this topology:
Bus topology
Bus Topology
Simplest topology. Consists of a trunk cable that every workstation connects to.
Cheap - Requires little cabling
Easy to install
Diffiuclt to reconfigure (like adding a new workstation). A break in the bus disables the entire network.
Name this network topology:
Star Topology
Star Topology
All devices connect to a central hub/switch.
Easy to add/remove workstations
Fault tolerant - If a single workstation goes down, the entire network doesn’t go down.
More expensive to install - more cable and a central device is needed
Single Point of failure - The central hub goes, the entire network goes.
Name this network topology:
Ring topology
Describe the ring topology
Each computer connects to two other computers, joining them in a circle and creating a unidirection path where messages move from workstation to workstation.
Easy to install
Difficult to add new computers
The entire network will go down if a single workstation goes down.
Name this network topology:
Mesh Topology
Describe the mesh topology
Every device is connected to every other device.
Most complex physical design.
Every expensive to install and maintain
Highest fault tolerance.
Describe hybrid topology
A mix of one or more topologies.
Example: PCs connected to a central hub is a star topology.
Change the hub to a switch, which isolates each PC to its own collission domain, and now you have a star topology made up of many bus topologies.
OSI Model
A theoretical networking model
IEEE
The Institute of Electrical and Electronics Engineers
The committee of the IEEE to create standards for types of networks.
802
802.2
Logical Link Control
802.3
CSMA/CD (Ethernet) LAN
Defines eithernet communication.
Also defines a collission detection protocol, preventing network hosts from all talking at the same time.
802.5
Token Ring LAN
802.6
MAN
802.11
Wireless Networks
MAC
Media Access Control
Sublayer of the data link layer of the OSI model.
Watches out for data collissions and manages MAC addresses.
LLC
Logical Link Control
Sublayer of the data link layer of the OSI model
Manages data link communications
CSMA/CD
Carrier Sense Multipel Access with Collision Detection
Half-Duplex Communication
A NIC configured for half-duplex can only send or receive at one time, not both.
Full-duplex communication
A NIC configured for full duplex communication can send and receive data at the same time.
MAC Address
The unique hardware address of a NIC.
Three main types of physical cabling used to connect devices to a network
Coaxial (coax)
Twiest-pair
fiber-optic
Coaxial Cable
Contains a center conductor core made of copper, surrounded by a plastic jacket with a braided shield over it. The entire thing is covered with outer insulation made of teflon or plastic.
Name that cable:
Coax
PVC
Polyvinyl Chloride
Common plastic used to cover network cables.
Produces a poisonous gas with burned.
Plenum-rated coating
Coating for cabling that doesn’t produce toxic gases when burned.
Two popular standards for cabling when coax was used
RG-8
RG-58A/U
RG-8
Thicknet
Maximum segment distance of 500 meters
Used for network backbones
RG-58A/U
Thinnet
Maximum segment distance of 185 meters.
RG rating for satellite / cable TV and cable modems
RG-6 and RG-59 are used for cable TV
RG-6 is also used for satellite and cable modems
Ethernet implementation of RG-8
10Base5
This means it operates at 10Mbps
Is Baseband
And has a maximum cable segment of 500 meters
Ethernet implementation of RG-58AU
10Base2
This mean it has a speed of 10Mbps
Is Baseband
And has a maximum cable segment of 185 meters
(Yes, that’s a 2 at the end of that., so you’d think it’s 200 meters. Its 185 meters. They round up to get the 2. It’s a thing.)
Vampire Tap
The tool used to connect two ticknet cables together
Name these connectors:
BNC Connectors (British Navel Connectors)
Used to connect thinnet cables.
Name this connector:
F-connector
Used with cable TV
What is the most popular type of cabling?
Twisted-Pair cabling
Name this cabling:
Twisted Pair
Twisted Pair Cabling
Consists of several pairs of wire twisted around each other within an insulated jacket.
Two types of twisted pair cabling
STP (Shielded twisted pair)
UTP (unshielded twisted pair)
What is the difference between STP and UTP?
STP has an extra layer of braided foil shielding surrounding the wires to decrease eletrical interference.
UTP has PVC or plenum-rated coating but no foild shield to protect it from interferenc.
UTP comes in eight grades that offer different levels of performance. Name them.
Cat 1
Cat 2
Cat 3
Cat 4
Cat 5
Cat 5e
Cat 6
Cat 6a
What is the maximum transmission distance of all UTP grades of cable?
100 meters
Except for CAT6, which can transfer data up to 100 meters but not at its maximum speed of 10Gbps.
CAT 1
Two twiested pairs, making four wires
For voice-transmission only
Cat 2
Four twisted pairs, making 8 wires
Can handle transmission speeds up to 4Mbps
Cat 3
4 twisted pairs, 8 wires
Transits up to 10Mbps
Cat 4
4 twisted pairs, 8 wires
Can transfer up to 16Mbps
Cat 5
4 twisted pairs, 8 wires
Can transfer 100Mbps
Cat 5e
4 twisted pairs, 8 wires
Can transmit up to 1Gbps.
Different from CAT5 in that the twisted pairs of wires are physically separated and contain more twists per foot, providing maximum interference protection
Cat 6
4 twisted pairs, 8 wires
Can transfer up to 10Gbps, but only at reduced distances.
Cat 6a
4 twisted pairs, 8 wires
Can transfer up to 10Gbps but at longer distances – the full 100 meters.
Two connector types for UTP cabling
RJ-11 (phone)
RJ-45 (data)
Two wiring standards to ensure that each ofthe 8 wires used in UTP fit into the right spots on the RJ-45 connector
568A
568B
Fiber-Optic Cabling
Thin, flexible galss or plastic fiber surrounded by a rubberized outer coating.
Transmission speeds from 100Mbps to 10Gbps
Max distance of several miles.
Uses light instead of electric voltages to transmit data
Immune to electrical interference
Name this cabling:
Fiber-Optic
Two varieties of fiber-optic cabling
single-mode
multi-mode
SMF
Single-mode fiber
Uses only a single mode of light to propagate through the fiber cable.
uses lasers that travel straight down the cable.
Supports higher bandwidth at longer distances
Up to 10Gbps for up to 40KM
MMF
Multi-mode fiber
Can transmit up to 10Gbps for up to 550 mters.
Uses multiple modes (paths) of light to propagate simulataneously. – The light bounces off the cable walls, which causes the signal to weaken faster than SMF
Three of the most common fiber-optic connectors
ST (Straight tip)
SC (Square Connector / subscriber connector)
LC (local connector)
Name this fiber-optic connector:
ST (Straight Tip)
Name this fiber-optic connector:
Subscriber Connector
Name this fiber-optic connector:
LC (Local Connector)
ST
Straight TIp Connector
Developed by AT&T
Most widely used fiber-toptic connector
SC
Suscriber Connector
AKA Square Conector
Type of fiber-optic connector
LC
Local Conector
Developed by Lucent Technologies
Type of fiber connector
Mini-form factor connector (MMF)
Name this tool:
Crimper
Crimper is used for
Putting connectors at the end of a cable.
Name this tool:
Multimeter
Multimeter is used for
Electronic measuring. Can measure voltage, current and resistance on a wire.
Toner Probe is used for
Tracing a wire in a wall from one location to another.
Also known as ‘fox and hound’
Name this tool:
Toner Probe
Name this tool:
Loopback plug
Cable Tester is used for
Testing network cables to ensure they work. Should tell you the type of cable and whether the twisted pairs line up to standard.
Loopback Plug is used for
Testing the ability of a network adapter (NIC) to send and receive data.
Plugged into the NIC and then a loopback test is performed using troubleshooting software, which will tell you if the card is working properly or not.
Name this tool:
Punch-down tool
Punch-Down Tool is used for
Allows you to connect (punch down) the eposed ends of a wire into a wiring harness, like a 100 block, which is pictured below:
Modem
Allows you to connect to a network or the Internet using plain old phone lines.
Fasted transfer rate was 56Kbps.
Access Points
Commonly used to reference a wireless access point.
May also refer to any point that allows a user on to a network
Hub
Deviced used to link several compuers together.
Not used anymore.
Bridges
Use to divid network segments into multipel collission domains, which isolates traffic, preventing unwanted traffic from entering a segment when there are no recipients on that segment.
Switch
Do what bridges do, but do so for as many devices as hubs connect.
Switches examine incoming packets and forward the traffic just to the recipient, instead of broadcasting it to all connected devices.
Routers
Connect multiple networks. Determine the best path to send data when more than one path exists.
NAS
Network attached storage.
Acts like a hard drive directly attached to the netork.
Act as a file server.
Firewall
Hardware or software solution that serves as your network’s security gaurd.
The most important device on networks connected to the Internet.
Firewalls can have up to three zones or sides. What are they?
Public (facing the Internet)
Private (Facing the network)
DMZ (Private, but not connected to the private network)
DMZ
Demilitarized zone.
Intermediary network for hosting websites, email servers, etc.
For when you need to protect your servers from some types of traffic, but they must be open to other types that a private network would not normally be open to.
Also, allows you to segment servers that are more vulterable to attack (web servers) from your private network
ACL
Access Control List
Set of rules that determines which traffic gets through a firewall and which traffic is blocked.
VoIP
Voice over Internet Protocol
Delivers voice communications over the Internet
Allow users to send data, video and voice at the same time over the same Internet connection.
Internet Appliance
Specialied hardware device that exists solely to connect to the Internet. Can be used for web browsing, email, etc. Intended to be lower-cost alternatives to laptop computers.
