chapter 6 - network hardware

Chapter SixChapter SixNetworkingNetworking

HardwareHardware

Network AdaptersNetwork Adapters

Also called network interface cards (NICs)Also called network interface cards (NICs)

Connectivity devices enabling a workstation, Connectivity devices enabling a workstation, server, printer, or other node to receive and server, printer, or other node to receive and transmit data over the network mediatransmit data over the network media

In most modern network devices, network In most modern network devices, network adapters contain the data transceiveradapters contain the data transceiver

Types of Network AdaptersTypes of Network Adapters

For a desktop or tower PC, network adapter For a desktop or tower PC, network adapter is likely to be a type of is likely to be a type of expansion boardexpansion board Expansion boards connect to the system board Expansion boards connect to the system board

through through expansion slotsexpansion slots

The circuit used by the system board to The circuit used by the system board to transmit data to the computer’s components transmit data to the computer’s components is the computer’s is the computer’s busbus


PC bus types you PC bus types you may encounter:may encounter:

Industry Standard Industry Standard Architecture (ISA)Architecture (ISA)

MicroChannel MicroChannel Architecture (MCA)Architecture (MCA)

Extended Industry Extended Industry Standard Standard Architecture (EISA)Architecture (EISA)

Peripheral Peripheral Component Component Interconnect (PCI)Interconnect (PCI)

Figure 6-1: The four primary bus architectures


Figure 6-2: A system

board with multiple bus

types


PCMIAPCMIA Developed in early 1990s to provide standard interface for Developed in early 1990s to provide standard interface for

connecting any type of device to a portable computerconnecting any type of device to a portable computer More commonly known as More commonly known as PC CardsPC Cards

Figure 6-3: Typical PC Card network adapter


USB (universal USB (universal serial bus) portserial bus) port Standard Standard

external bus external bus that can be that can be used to used to connect connect multiple types multiple types of peripheralsof peripherals

Figure 6-4: A USB network adapter


Figure 6-5: A parallel port network adapter


Figure 6-6: Wireless network adapters


Figure 6-7: A variety of

Ethernet network adapters


Figure 6-8: Token Ring

network adapters


Figure 6-9: Ethernet network adapters for printers

Installing Network AdaptersInstalling Network Adapters

To install modern network adapters, first install To install modern network adapters, first install hardware, then install software shipped with NIChardware, then install software shipped with NIC

In some cases you must perform a third step:In some cases you must perform a third step: Configure the Configure the firmwarefirmware

Electrically erasable programmable read-only Electrically erasable programmable read-only memory (EEPROM)memory (EEPROM) Type of ROM found on a circuit boardType of ROM found on a circuit board Configuration information can be erased and rewritten Configuration information can be erased and rewritten

through electrical pulsesthrough electrical pulses

Installing and Configuring Network Installing and Configuring Network Adapter HardwareAdapter Hardware

Figure 6-10: A properly inserted network adapter


Figure 6-11: Installing a PC Card network adapter


JumperJumper Small, removable piece of plastic that contains a Small, removable piece of plastic that contains a

metal receptaclemetal receptacle

Figure 6-12: A jumper and a row of pins indicating two different settings


DIP switchDIP switch Small, plastic toggle switch that represents “on” or “off” statusSmall, plastic toggle switch that represents “on” or “off” status

Figure 6-13: DIP switches on a NIC

Installing and Configuring Network Installing and Configuring Network Adapter SoftwareAdapter Software

Ensure that the correct device driver is Ensure that the correct device driver is installed for the network adapter and that it installed for the network adapter and that it is configured properlyis configured properly

Device driverDevice driver Software that enables an attached device to Software that enables an attached device to

communicate with computer’s operating communicate with computer’s operating systemsystem

IRQ (Interrupt Request Line)IRQ (Interrupt Request Line)

Message to the computer that instructs it to Message to the computer that instructs it to stop what it is doing and pay attention to stop what it is doing and pay attention to something elsesomething else

An An interruptinterrupt is the wire on which a device is the wire on which a device issues voltage to signal this requestissues voltage to signal this request

Each interrupt must have a unique Each interrupt must have a unique IRQ IRQ numbernumber

IRQ (Interrupt Request Line)IRQ (Interrupt Request Line)

Table 6-1: IRQ assignments

Memory Range Memory Range and Base I/O Portand Base I/O Port

Memory rangeMemory range Hexadecimal number indicating the area Hexadecimal number indicating the area

memory that the network adapter and CPU memory that the network adapter and CPU will use for exchanging, or buffering, the datawill use for exchanging, or buffering, the data

Base I/O portBase I/O port Setting that specifies, in hexadecimal Setting that specifies, in hexadecimal

notation, which area of memory will act as a notation, which area of memory will act as a channel for moving data between the network channel for moving data between the network adapter and CPUadapter and CPU

Choosing the Right Network AdapterChoosing the Right Network Adapter

Table 6-2: Network adapter characteristics

RepeatersRepeaters

Connectivity devices that regenerate and Connectivity devices that regenerate and amplify an analog or digital signalamplify an analog or digital signal

Figure 6-16: Repeaters

HubsHubs

Multiport repeater containing multiple ports Multiport repeater containing multiple ports to interconnect multiple devicesto interconnect multiple devices

Figure 6-17: Detailed diagram of a hub

HubsHubs

Elements shared by most hubs:Elements shared by most hubs: PortsPorts Uplink portUplink port Port for management consolePort for management console Backbone portBackbone port Link LEDLink LED

HubsHubs

Elements shared by most hubs (cont.):Elements shared by most hubs (cont.): Traffic (transmit or receive) LEDTraffic (transmit or receive) LED Collision LED (Ethernet hubs only)Collision LED (Ethernet hubs only) Power supplyPower supply Ventilation fanVentilation fan

HubsHubs

Figure 6-18: Hubs in a network design

HubsHubs

Passive hubsPassive hubs Only repeats signalOnly repeats signal

Intelligent hubsIntelligent hubs Possesses processing capabilitiesPossesses processing capabilities

Standalone HubsStandalone Hubs

Hubs that serve a group of computers that Hubs that serve a group of computers that are isolated from the rest of the networkare isolated from the rest of the network Best suited to small, independent departments, Best suited to small, independent departments,

home offices, or test lab environmentshome offices, or test lab environments

Disadvantage to using a single hub for many Disadvantage to using a single hub for many connection ports is that it introduces a connection ports is that it introduces a single single point of failurepoint of failure on the network on the network

Stackable HubsStackable Hubs

Physically designed to be linked with other hubs in a single Physically designed to be linked with other hubs in a single telecommunications closettelecommunications closet

Figure 6-20: Stackable hubs

Figure 6-21: Rack-mounted stackable hubs

Modular Hubs and Intelligent HubsModular Hubs and Intelligent Hubs

Modular hubsModular hubs Provide a number of interface options within one Provide a number of interface options within one

chassischassis

Intelligent hubsIntelligent hubs Also called Also called managed hubsmanaged hubs Network administrators can store the information Network administrators can store the information

generated by intelligent hubs in a generated by intelligent hubs in a MIB MIB (management information base)(management information base)

Installing a HubInstalling a Hub

As with network As with network adapters, the adapters, the best way to best way to ensure a hub is ensure a hub is properly installed properly installed is to follow the is to follow the manufacturer’s manufacturer’s guidelinesguidelines

Figure 6-22: Connecting a workstation to a hub

Choosing the Right HubChoosing the Right Hub

Factors to consider when selecting the Factors to consider when selecting the right hub for your network:right hub for your network: PerformancePerformance CostCost Size and growthSize and growth SecuritySecurity Management benefitsManagement benefits ReliabilityReliability

SwitchesSwitches

Subdivide a Subdivide a network into network into smaller smaller logical logical piecespieces

Figure 6-25: Examples of LAN switches

Cut-Through Mode andCut-Through Mode andStore and Forward ModeStore and Forward Mode

Cut-through modeCut-through mode Switching mode in which switch reads a Switching mode in which switch reads a

frame’s header and decides where to forward frame’s header and decides where to forward the data before it receives the entire packetthe data before it receives the entire packet

Cut-through switches can detect Cut-through switches can detect runtsrunts, or , or packet fragmentspacket fragments

Store and forward modeStore and forward mode Switching mode in which switch reads the Switching mode in which switch reads the

entire data frame into its memory and checks entire data frame into its memory and checks it for accuracy before transmitting the it for accuracy before transmitting the informationinformation

Using Switches to Create Using Switches to Create VLANsVLANs

Virtual local area networks (VLANs)Virtual local area networks (VLANs) Network within a network that is logically Network within a network that is logically

defined by grouping its devices’ switch ports defined by grouping its devices’ switch ports in the same broadcast domainin the same broadcast domain

Broadcast domainBroadcast domain Combination of ports that make up a Layer 2 Combination of ports that make up a Layer 2

segment and must be connected by a Layer 3 segment and must be connected by a Layer 3 devicedevice

Using Switches to Create Using Switches to Create VLANsVLANs

Figure 6-26: A simple VLAN design

RoutersRouters

Multiport connectivity deviceMultiport connectivity device

Can integrate LANs and WANs running at Can integrate LANs and WANs running at different transmission speeds and using a different transmission speeds and using a variety of protocolsvariety of protocols

Routers operate at the Network layer Routers operate at the Network layer (Layer 3) of the OSI Model(Layer 3) of the OSI Model

Router Features and FunctionsRouter Features and Functions

Modular routerModular router Router with Router with

multiple slots multiple slots that can hold that can hold different different interface cards interface cards or other or other devicesdevices

Figure 6-27: Routers


Filter out broadcast transmission to alleviate Filter out broadcast transmission to alleviate network congestionnetwork congestion

Prevent certain types of traffic from getting to a Prevent certain types of traffic from getting to a networknetwork

Support simultaneous local and remote activitySupport simultaneous local and remote activity

Provide high network fault tolerance through Provide high network fault tolerance through redundant componentsredundant components

Monitor network traffic and report statistics to a MIBMonitor network traffic and report statistics to a MIB

Diagnose internal or other connectivity problems Diagnose internal or other connectivity problems and trigger alarmsand trigger alarms


Static routingStatic routing Technique in which a network administrator programs Technique in which a network administrator programs

a router to use a specified paths between nodesa router to use a specified paths between nodes

Dynamic routingDynamic routing Automatically calculates best path between nodes Automatically calculates best path between nodes

and accumulates this information in a routing tableand accumulates this information in a routing table

HopHop Term used in networking to describe each trip data Term used in networking to describe each trip data

take from one connectivity device to anothertake from one connectivity device to another


Figure 6-28: The placement of routers on a LAN

Routing ProtocolsRouting Protocols

To determine the To determine the best pathbest path, routers , routers communicate with each other through communicate with each other through routing routing protocolsprotocolsIn addition to its ability to find the best path, a In addition to its ability to find the best path, a routing protocol can be characterized according routing protocol can be characterized according to its convergence time and bandwidth overheadto its convergence time and bandwidth overhead Convergence timeConvergence time

The time it takes for a router to recognize a best path in the The time it takes for a router to recognize a best path in the event of a change or outageevent of a change or outage

Bandwidth overheadBandwidth overheadBurden placed on an underlying network to support the Burden placed on an underlying network to support the routing protocolrouting protocol

Routing ProtocolsRouting Protocols

The four most common routing protocols:The four most common routing protocols: RIP (Routing Information Protocol) for IP and RIP (Routing Information Protocol) for IP and

IPXIPX OSPF (Open Shortest Path First) for IPOSPF (Open Shortest Path First) for IP EIGRP (Enhanced Interior Gateway Routing EIGRP (Enhanced Interior Gateway Routing

Protocol) for IP, IPX, and AppleTalkProtocol) for IP, IPX, and AppleTalk BGP (Border Gateway Protocol) for IPBGP (Border Gateway Protocol) for IP

chapter 6 - network hardware

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network best

network media

network design

modern network adapters

wireless network adapters

network adapter software

usb network adapter

inserted network adapter