Local Area Local Area ConnectionConnection

Physical Network Physical Network ArchitecturesArchitectures Ethernet (most popular)Ethernet (most popular)

Wireless LANWireless LAN

Token RingToken Ring

FDDI (Fiber Distributed Data FDDI (Fiber Distributed Data Interface)Interface)

Network Architecture Network Architecture TerminologyTerminology Network adapterNetwork adapter

– Provides direct connection between PC and Provides direct connection between PC and network; usually an expansion card (NIC)network; usually an expansion card (NIC)

– Matches type and speed of physical networkMatches type and speed of physical network

– Network port matches connectors on Network port matches connectors on networknetwork

Network Architecture Network Architecture Terminology (Terminology (continuedcontinued))

Network protocolsNetwork protocols

– OS protocols (eg, NetBEUI, TCP/IP)OS protocols (eg, NetBEUI, TCP/IP)

– Hardware protocols (eg, Ethernet, Token Hardware protocols (eg, Ethernet, Token Ring)Ring)

Data transmissionData transmission

– Packets, datagrams, or framesPackets, datagrams, or frames

OS Protocol - NetBEUIOS Protocol - NetBEUI

Pronounced Pronounced net-booey,net-booey, NetBEUI is short for NetBEUI is short for NetBNetBios ios EExtended xtended UUserser I Interface.nterface. It is an enhanced version It is an enhanced version of the NetBIOS protocol used by network operating of the NetBIOS protocol used by network operating systems such as LAN Manager, LAN Server, systems such as LAN Manager, LAN Server, Windows for Workgroups, Windows 95 and Windows Windows for Workgroups, Windows 95 and Windows NT NT

NetBEUI was originally designed by IBM for their LanNetBEUI was originally designed by IBM for their Lan Manager server and later extended by Microsoft Manager server and later extended by Microsoft and Novelland Novell

OS Protocol – TCP/IPOS Protocol – TCP/IP

(pronounced as separate letters) Short for (pronounced as separate letters) Short for TTransmission ransmission CControl ontrol PProtocol/rotocol/IInternet nternet PProtocol,rotocol, the the suite of communications protocols used to connect suite of communications protocols used to connect hosts on the Internethosts on the Internet

TCP/IP uses several protocols, the two main ones TCP/IP uses several protocols, the two main ones being TCP and IP. TCP/IP is built into the UNIX being TCP and IP. TCP/IP is built into the UNIX operating system and is used by theoperating system and is used by the Internet, Internet, making it the de facto standard for transmitting making it the de facto standard for transmitting data over networksdata over networks

Even network operating systems that have their Even network operating systems that have their own protocols, such as Netware, also support TCP/IPown protocols, such as Netware, also support TCP/IP

Ethernet Variations, Ethernet Variations, Distinguished by Distinguished by SpeedSpeed

Ethernet Cable TypesEthernet Cable Types

continued…

Ethernet Cable Types Ethernet Cable Types ((continuedcontinued))

Ethernet TopologyEthernet Topology

Bus topologyBus topology

– Connects each node in a lineConnects each node in a line

– Has no central connection pointHas no central connection point

Star topologyStar topology

– Connects all nodes to a centralized hubConnects all nodes to a centralized hub

– More popular; easier to maintainMore popular; easier to maintain

– Patch cables and crossover cablesPatch cables and crossover cables

Bus and Star Bus and Star TopologiesTopologies

Ethernet Hub Ethernet Hub Broadcasting a Data Broadcasting a Data PacketPacket

A HubA Hub

Star Bus TopologyStar Bus Topology

RepeatersRepeaters

Amplify signals on a networkAmplify signals on a network

Help overcome limitations on length of cables Help overcome limitations on length of cables that can be used; signals can travel fartherthat can be used; signals can travel farther

Two kindsTwo kinds

– Amplifier repeaterAmplifier repeater

– Signal-regenerating repeater (used by Signal-regenerating repeater (used by Ethernet)Ethernet)

Repeaters (Repeaters (continuedcontinued))

Wireless LANsWireless LANs

Use radio waves or infrared light to Use radio waves or infrared light to connect computers or devicesconnect computers or devices– Wireless NIC includes antenna to send Wireless NIC includes antenna to send

and receive signalsand receive signals StandardsStandards

– 1999 IEEE 802.11b (Wi-Fi or AirPort)1999 IEEE 802.11b (Wi-Fi or AirPort)– BluetoothBluetooth

Slower than wired networksSlower than wired networks Security is an issueSecurity is an issue

Wireless LANs – Wireless LANs – (continued)(continued)

Wireless LANs – Wireless LANs – (continued)(continued)

Wireless LANs Wireless LANs ((continuedcontinued))

Token RingToken Ring

Physical star; logical ringPhysical star; logical ring

Data packet is preceded by a tokenData packet is preceded by a token

Transmits data at 4 Mbps or 16 MbpsTransmits data at 4 Mbps or 16 Mbps

Uses a centralized device called a MAU Uses a centralized device called a MAU (Multistation Access Unit)(Multistation Access Unit)

Uses UTP or STP cables (two twisted Uses UTP or STP cables (two twisted pairs)pairs)

Uses RJ-45 or UDC connectors Uses RJ-45 or UDC connectors

FDDIFDDI

Uses tokens; structured as a ring, but Uses tokens; structured as a ring, but does not require a centralized hubdoes not require a centralized hub

Multiple nodes can have data on the Multiple nodes can have data on the ring at the same timering at the same time

Provides data transfer at 100 MbpsProvides data transfer at 100 Mbps Used as:Used as:

– Network technology for a large LANNetwork technology for a large LAN– Backbone network to connect several Backbone network to connect several

LANsLANs

FDDI – FDDI – (continued)(continued)

FDDI Uses Counter-Rotating Primary and Secondary Rings

More info: http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/fddi.htm

How NICs WorkHow NICs Work

Plug into motherboard expansion Plug into motherboard expansion slotslot

Provide port(s) on back of card for Provide port(s) on back of card for connection to networkconnection to network

Manage communication and Manage communication and hardware network protocol for the hardware network protocol for the PCPC

Network CardsNetwork Cards

a. FDDI b. Token ring

c. Ethernet d. Wireless

Network CardsNetwork Cards

Send and receive data:Send and receive data:– To and from system bus in parallelTo and from system bus in parallel– To and from network in seriesTo and from network in series

Use a transceiver for signal conversionUse a transceiver for signal conversion Identified by a MAC addressIdentified by a MAC address Require an IRQ and an I/O address Require an IRQ and an I/O address

rangerange May be PnP; legacy cards can use May be PnP; legacy cards can use

jumpers or DIP switchesjumpers or DIP switches

Ethernet Combo CardEthernet Combo Card

Considerations When Considerations When Selecting a Network Selecting a Network CardCard Speed and type of networkSpeed and type of network

Type of cable (shielded twisted-Type of cable (shielded twisted-pair, coaxial, or fiber-optic)pair, coaxial, or fiber-optic)

Type of slot (PCI or ISA)Type of slot (PCI or ISA)

Segmenting a NetworkSegmenting a Network

Communication on a local network Communication on a local network uses MAC address of NIC to identify uses MAC address of NIC to identify the destination computer; the destination computer; – Other computers discard the packet Other computers discard the packet

because it is not addressed to thembecause it is not addressed to them Bridges and switchesBridges and switches

– Reduce traffic on each segment and Reduce traffic on each segment and improve network performanceimprove network performance

– More intelligent than hubsMore intelligent than hubs

How Bridges WorkHow Bridges Work

Bridges and SwitchesBridges and Switches

Bridges and Switches Bridges and Switches ((continuedcontinued)) BridgesBridges

– Send broadcast messages; not good for Send broadcast messages; not good for large networkslarge networks

– Effective at separating high-volume areas Effective at separating high-volume areas on a LANon a LAN

– Best for connecting LANs that do not Best for connecting LANs that do not communicate outside their immediate communicate outside their immediate networknetwork

Bridges and Switches Bridges and Switches ((continuedcontinued)) SwitchesSwitches

– Send a packet only to network Send a packet only to network segment for which it is destinedsegment for which it is destined

Both keep source and destination Both keep source and destination MAC addresses in routing tables MAC addresses in routing tables and learn new addressesand learn new addresses

Bridges Compared Bridges Compared with Switcheswith Switches

Windows on a NetworkWindows on a Network

Workgroup model and domain modelWorkgroup model and domain model Networking protocols supported at Networking protocols supported at

physical levelphysical level– EthernetEthernet– ATMATM– Token RingToken Ring

Protocols supported at OS levelProtocols supported at OS level– TCP/IP TCP/IP – IPX/SPXIPX/SPX– NetBEUINetBEUI

Windows on a Network Windows on a Network ((continuedcontinued))

OS ProtocolsOS Protocols

Automatically bind themselves to Automatically bind themselves to any NICs they findany NICs they find

More than one can be associated More than one can be associated with a single NICwith a single NIC

Addressing on a Addressing on a NetworkNetwork

MAC MAC addressaddress

Unique address permanently embedded in a Unique address permanently embedded in a NIC; identifies a device on a LANNIC; identifies a device on a LAN

Expressed as six pairs of hexadecimal Expressed as six pairs of hexadecimal numbers and lettersnumbers and letters

Used only by devices inside local networkUsed only by devices inside local network

IP addressIP address 32-bit address consisting of a series of four 8-32-bit address consisting of a series of four 8-bit numbers separated by periodsbit numbers separated by periods

Identifies a computer or device on a TCP/IP Identifies a computer or device on a TCP/IP network network

Character-Character-based based namesnames

Include domain names, host names (Windows Include domain names, host names (Windows 2000/XP), NetBIOS names (Windows 98)2000/XP), NetBIOS names (Windows 98)

Identify a PC with letters; easier to rememberIdentify a PC with letters; easier to remember Name resolution services: DNS and Microsoft Name resolution services: DNS and Microsoft

WINSWINS

Port Port addressaddress

Number that identifies a program or service Number that identifies a program or service running on a computer to communicate over running on a computer to communicate over the networkthe network

Network ConfigurationNetwork Configuration

MAC Addresses and IP MAC Addresses and IP AddressesAddresses

IP ConfigurationIP Configuration

MAC Addresses and IP MAC Addresses and IP AddressesAddresses

Classes of IP Classes of IP AddressesAddresses

IP AddressesIP Addresses

Different Ways of Different Ways of Assigning IP AddressesAssigning IP Addresses

Public, private, and reserved IP Public, private, and reserved IP addressesaddresses

Dynamically assigned IP addressesDynamically assigned IP addresses

– DHCP serverDHCP server

Network Address Translation (NAT)Network Address Translation (NAT)

Reserved IP AddressesReserved IP Addresses

Configuring a DHCP Configuring a DHCP ServerServer

Using NAT (Network Using NAT (Network Address Translation)Address Translation)

Using NAT (Network Using NAT (Network Address Translation) – Address Translation) – (Continued)(Continued)

Short for Network Address Translation, an Internet standard that enables a local-area network (LAN) to use one set of IP addresses for internal traffic and a second set of addresses for external traffic

A NAT box located where the LAN meets the Internet makes all necessary IP address translations. NAT serves three main purposes:

• Provides a type of firewall by hiding internal IP addresses

• Enables a company to use more internal IP addresses. Since they're used internally only, there's no possibility of conflict with IP addresses used by other companies and organizations

• Allows a company to combine multiple ISDN connections into a single Internet connection

How Computers Find How Computers Find Each Other on a LANEach Other on a LAN1.1. Checks NetBIOS name cacheChecks NetBIOS name cache

2.2. Queries WINS server, if it has its IP addressQueries WINS server, if it has its IP address

3.3. Sends broadcast message to all computers Sends broadcast message to all computers on LAN asking for IP address of computer on LAN asking for IP address of computer with broadcasted NetBIOS namewith broadcasted NetBIOS name

4.4. Checks LMHosts fileChecks LMHosts file

5.5. If IP address still not discovered, computer If IP address still not discovered, computer assumes network is using DNS and checks assumes network is using DNS and checks Hosts fileHosts file

6.6. Queries DNS server, if it has its IP addressQueries DNS server, if it has its IP address

Installing a Network Card Installing a Network Card & Connecting to a & Connecting to a NetworkNetwork Physically install the card and device Physically install the card and device

driversdrivers

Configure the NIC using Windows so it Configure the NIC using Windows so it has appropriate addresses on the has appropriate addresses on the network and correct network protocolsnetwork and correct network protocols

Give the computer a nameGive the computer a name

Test the NIC to verify that PC can access Test the NIC to verify that PC can access resources on the networkresources on the network

Installing a NIC Using Installing a NIC Using Windows 2000/XPWindows 2000/XP

Installing a NIC Using Installing a NIC Using Windows 2000/XP Windows 2000/XP ((continuedcontinued))

Installing a NIC Using Installing a NIC Using Windows 2000/XP Windows 2000/XP ((continuedcontinued))

Installing and Installing and Configuring TCP/IP Using Configuring TCP/IP Using Windows 2000/XPWindows 2000/XP Will PC use dynamic or static addressing?Will PC use dynamic or static addressing?

If static addressing, what are IP address, If static addressing, what are IP address, subnet mask, and default gateway?subnet mask, and default gateway?

If you use DNS, what are the IP addresses If you use DNS, what are the IP addresses of the DNS servers?of the DNS servers?

If a proxy server is used to connect to If a proxy server is used to connect to other networks, what is IP address of other networks, what is IP address of proxy server?proxy server?

Dynamic AddressingDynamic Addressing

When you do NOT need static IP When you do NOT need static IP addressesaddresses

If you ONLY do things from the following list If you ONLY do things from the following list you do not need static IP addresses.you do not need static IP addresses.

– If you browse the Internet If you browse the Internet – If you send and receive e-mail via an offsite If you send and receive e-mail via an offsite

server (the normal method)server (the normal method)– If you download or upload filesIf you download or upload files– If you use Instant message services or chat If you use Instant message services or chat

servicesservices

Static AddressingStatic Addressing

When you need Static IP AddressesWhen you need Static IP Addresses

You need one or more Static IP addresses if any of the following are true:You need one or more Static IP addresses if any of the following are true:

You run one or more Web server's directly on your site that require external You run one or more Web server's directly on your site that require external access (from the Internet, or Extranet but not typically an Intranet) access (from the Internet, or Extranet but not typically an Intranet) You run one or more E-mail server's directly on your site that require You run one or more E-mail server's directly on your site that require external external access (from the Internet, or Extranet but not typically an access (from the Internet, or Extranet but not typically an Intranet)Intranet) You run one or more FTP server's directly on your site that require external You run one or more FTP server's directly on your site that require external access (from the Internet, or Extranet but not typically an Intranet)access (from the Internet, or Extranet but not typically an Intranet) You run any other service or 'Application' that requires external access You run any other service or 'Application' that requires external access (from the Internet or an Extranet). Some Financial Terminal Client (from the Internet or an Extranet). Some Financial Terminal Client applications require that you have a static IP address for licensing applications require that you have a static IP address for licensing purposespurposes You allow 'incoming' Video Conferencing you You allow 'incoming' Video Conferencing you maymay need to use static IP need to use static IP addresses addresses

How Many IP AddressesHow Many IP Addresses

How many IP Addresses do you needHow many IP Addresses do you need

The following 'rules of thumb' apply to calculate the number of The following 'rules of thumb' apply to calculate the number of required IP addressesrequired IP addresses

If you run one of any type of server (FTP, Web, E-mail etc.) on If you run one of any type of server (FTP, Web, E-mail etc.) on site then you only require a single Static IP addresssite then you only require a single Static IP address

If you run one copy of any application which uses Fixed Port If you run one copy of any application which uses Fixed Port Numbers Numbers you only need a single Static IP addressyou only need a single Static IP address

In all other cases you need as many Static IP addresses as In all other cases you need as many Static IP addresses as there there are Applications or Servers that use the same Port are Applications or Servers that use the same Port NumberNumber

Installing a Wireless Installing a Wireless NICNIC Use NIC’s configuration software to Use NIC’s configuration software to

specify wireless network parametersspecify wireless network parameters

Computer must be within acceptable Computer must be within acceptable range of an access point or another range of an access point or another wireless device that it will communicate wireless device that it will communicate with directlywith directly

– Distance determined by type of technology Distance determined by type of technology used – most likely 802.11bused – most likely 802.11b

Installing a Wireless Installing a Wireless NIC (NIC (continuedcontinued))

Installing a Wireless Installing a Wireless NIC (NIC (continuedcontinued))

Installing a Wireless Installing a Wireless NIC (NIC (continuedcontinued))

Using Resources on Using Resources on the Networkthe Network LANLAN

– Assign all users to same workgroup or Assign all users to same workgroup or domain with My Network Places (Windows domain with My Network Places (Windows 2000/XP) or Network Neighborhood 2000/XP) or Network Neighborhood (Windows 9x)(Windows 9x)

Peer-to-peer networkPeer-to-peer network

– Install Client for Microsoft Networks and Install Client for Microsoft Networks and File and Printer SharingFile and Printer Sharing

– Share resourcesShare resources

Installing Windows XP Installing Windows XP Components Needed to Components Needed to Share ResourcesShare Resources

Sharing Files and Sharing Files and Folders with the Folders with the WorkgroupWorkgroup

Sharing Files and Folders Sharing Files and Folders with the Workgroup with the Workgroup ((continuedcontinued))

Network Drive MapsNetwork Drive Maps

Using NFS client/software, network Using NFS client/software, network drive map makes one PC (client) drive map makes one PC (client) appear to have new hard drive appear to have new hard drive when that hard drive space is when that hard drive space is actually on another host computer actually on another host computer (server)(server)

Use Windows Explorer to map a Use Windows Explorer to map a network drivenetwork drive

Results of Drive Results of Drive MappingMapping

Symptoms of NIC Symptoms of NIC ProblemsProblems

Cannot make connection to networkCannot make connection to network

My Network Places or Network My Network Places or Network Neighborhood does not show other Neighborhood does not show other computers on networkcomputers on network

Error message appears during installation Error message appears during installation of NIC driversof NIC drivers

Device Manager shows yellow exclamation Device Manager shows yellow exclamation point or red X beside name of NICpoint or red X beside name of NIC

No lights on NICNo lights on NIC

Troubleshooting Troubleshooting Network ConnectionsNetwork Connections Check the following:Check the following:

– Cabling and ports for PCCabling and ports for PC– NIC itselfNIC itself– BIOSBIOS– Device driversDevice drivers

Troubleshooting toolsTroubleshooting tools– Ping (TCP/IP utility)Ping (TCP/IP utility)– Ipconfig (Windows NT/2000/XP)Ipconfig (Windows NT/2000/XP)– Winipcfg (Windows 9x)Winipcfg (Windows 9x)

Connecting Networks Connecting Networks with Routerswith Routers Use IP addresses to determine path by which Use IP addresses to determine path by which

to send a packet; to send a packet; – Tables determine most efficient available Tables determine most efficient available

routeroute Stateless devices - concerned about Stateless devices - concerned about

destination address; destination address; – Unconcerned about dataUnconcerned about data

Transmit data packet to remote network only Transmit data packet to remote network only if routable protocol was used to produce data if routable protocol was used to produce data packetpacket

Connecting Networks Connecting Networks with Routers (with Routers (continuedcontinued))

BrouterBrouter

Functions both as a bridge and a Functions both as a bridge and a routerrouter

– As a routerAs a router

Routes routable protocols (TCP/IP and Routes routable protocols (TCP/IP and IPX/SPX packets)IPX/SPX packets)

– As a bridgeAs a bridge

Forwards packets that are not routable Forwards packets that are not routable (NetBEUI packets) to other local networks(NetBEUI packets) to other local networks

Connecting Networks Connecting Networks with Bandwidth with Bandwidth TechnologiesTechnologies Bandwidth: measure of data capacityBandwidth: measure of data capacity Greater bandwidth = faster communicationGreater bandwidth = faster communication Common bandwidth technologiesCommon bandwidth technologies

– Regular telephone linesRegular telephone lines– Cable modemCable modem– ISDN (Integrated Services Digital Network)ISDN (Integrated Services Digital Network)– DSL (Digital Subscriber Line)DSL (Digital Subscriber Line)– Satellite accessSatellite access– Wireless accessWireless access

Bandwidth Bandwidth TechnologiesTechnologies

Bandwidth Bandwidth Technologies (Technologies (continuedcontinued))

Bandwidth Bandwidth Technologies (Technologies (continuedcontinued))

Bandwidth Bandwidth Technologies (Technologies (continuedcontinued))