View
221
Download
1
Tags:
Embed Size (px)
Citation preview
Institute of Technology Sligo - Dept of Computing
WANs and Router BasicsWANs and Router Basics
Semester 2Semester 2
Chapter 2: WANs & RoutersChapter 2: WANs & Routers
Chapter 3: Router CLIChapter 3: Router CLIPaul Flynn
Institute of Technology Sligo - Dept of Computing
Table of ContentsTable of Contents WAN DevicesWAN Devices
WAN StandardsWAN Standards
WAN TechnologiesWAN Technologies
Router BasicsRouter Basics
Router User Router User InterfaceInterface
Institute of Technology Sligo - Dept of Computing
WAN DevicesWAN Devices
Institute of Technology Sligo - Dept of Computing
WAN ServicesWAN Services WANs provide for the exchange of data WANs provide for the exchange of data
packets/frames between routers/bridges packets/frames between routers/bridges and the LANs they support. and the LANs they support.
A WAN interconnects LANs that are A WAN interconnects LANs that are usually separated by large geographic usually separated by large geographic areas. areas.
WANs connect devices. Such devices WANs connect devices. Such devices include...include...
Institute of Technology Sligo - Dept of Computing
RoutersRouters Routers offer many services including:Routers offer many services including:
InternetworkingInternetworking WAN serial interfacesWAN serial interfaces
Routers can operate as...Routers can operate as... Internal RoutersInternal Routers Backbone Routers Backbone Routers Area Border RoutersArea Border Routers Autonomous System Boundary RoutersAutonomous System Boundary Routers
Institute of Technology Sligo - Dept of Computing
WAN Bandwidth SwitchesWAN Bandwidth Switches
Service provider equipment that connects Service provider equipment that connects to WAN bandwidth for voice, data and to WAN bandwidth for voice, data and video communications.video communications.
Institute of Technology Sligo - Dept of Computing
ModemsModems
Also called CSU/DSUs (channel service Also called CSU/DSUs (channel service units/digital service units)units/digital service units)
Interface with voice-grade connection in Interface with voice-grade connection in order to convert analog signal to digital.order to convert analog signal to digital.
Represents the DCE side of the DTE/DCE Represents the DCE side of the DTE/DCE connection.connection.
More on DTE/DCE laterMore on DTE/DCE later
Institute of Technology Sligo - Dept of Computing
Communication ServersCommunication Servers
Concentrates dial-in and dial-out services.Concentrates dial-in and dial-out services. Equipment is usually at the service Equipment is usually at the service
provider’s site.provider’s site.
Institute of Technology Sligo - Dept of Computing
WAN StandardsWAN Standards
Institute of Technology Sligo - Dept of Computing
WAN StandardsWAN Standards
What layers of the OSI model do WAN What layers of the OSI model do WAN standards describe?standards describe? Physical and Data Link LayersPhysical and Data Link Layers
Institute of Technology Sligo - Dept of Computing
WAN Physical LayerWAN Physical Layer Protocols that describe how to provide electrical, Protocols that describe how to provide electrical,
mechanical, operational, and functional mechanical, operational, and functional connections for WAN services. connections for WAN services.
These services are most often obtained from These services are most often obtained from WAN service providers such as RBOCs, WAN service providers such as RBOCs, alternate carriers, post-telephone, and telegraph alternate carriers, post-telephone, and telegraph (PTT) agencies. (PTT) agencies.
Describes the interface between the data Describes the interface between the data terminal equipment (DTE) and the data circuit-terminal equipment (DTE) and the data circuit-terminating equipment (DCE).terminating equipment (DCE).
Institute of Technology Sligo - Dept of Computing
WAN Physical LayerWAN Physical Layer Typically, the DCE is the service provider and Typically, the DCE is the service provider and
the DTE is the attached device. the DTE is the attached device. In this model, the services offered to the DTE In this model, the services offered to the DTE
are made available through a modem or a are made available through a modem or a CSU/DSU.CSU/DSU.
Institute of Technology Sligo - Dept of Computing
WAN Physical LayerWAN Physical Layer Several physical layer standards specifying this Several physical layer standards specifying this
interface between the DTE & DCE are... interface between the DTE & DCE are... EIA/TIA-232 EIA/TIA-232 EIA/TIA-449 EIA/TIA-449 V.24 V.24 V.35 V.35 X.21 X.21 G.703 G.703 EIA-530 EIA-530
Institute of Technology Sligo - Dept of Computing
WAN Data-Link LayerWAN Data-Link Layer WAN data link protocols describe how frames WAN data link protocols describe how frames
are carried between systems on a single data are carried between systems on a single data link. link.
They include protocols designed to operate over They include protocols designed to operate over dedicated point-to-point, multipoint, and multi-dedicated point-to-point, multipoint, and multi-access switched services. access switched services.
WAN standards are defined and managed by a WAN standards are defined and managed by a number of recognized authorities, including the number of recognized authorities, including the following agencies: ITU-T, ISO, IETF, & EIAfollowing agencies: ITU-T, ISO, IETF, & EIA
Institute of Technology Sligo - Dept of Computing
WAN Data-Link EncapsulationsWAN Data-Link Encapsulations High-Level Data Link Control (HDLC) High-Level Data Link Control (HDLC)
Cisco default encapsulation; typically used Cisco default encapsulation; typically used between routers running Cisco IOS; between routers running Cisco IOS; replacing SDLCreplacing SDLC
Streamlined: no windowing or flow control Streamlined: no windowing or flow control may not be compatible with different vendors may not be compatible with different vendors
because of the way each vendor has chosen because of the way each vendor has chosen to implement it. to implement it.
HDLC supports both point-to-point and HDLC supports both point-to-point and multipoint configurations with minimal multipoint configurations with minimal overhead overhead
Institute of Technology Sligo - Dept of Computing
WAN Data-Link EncapsulationsWAN Data-Link Encapsulations
Frame Relay Frame Relay uses high-quality digital facilities; uses high-quality digital facilities; uses simplified framing with no error uses simplified framing with no error
correction mechanisms (connectionless!!);correction mechanisms (connectionless!!); it can send Layer 2 information much more it can send Layer 2 information much more
rapidly than other WAN protocols rapidly than other WAN protocols
Institute of Technology Sligo - Dept of Computing
WAN Data-Link EncapsulationsWAN Data-Link Encapsulations PPP (Point-to-Point Protocol)PPP (Point-to-Point Protocol)
Developed by IETF; replacing SLIPDeveloped by IETF; replacing SLIP Contains a field to identify the network layer Contains a field to identify the network layer
protocolprotocol PPP can check for link quality during PPP can check for link quality during
connection establishmentconnection establishment Supports PAP (Password Authentication Supports PAP (Password Authentication
Protocol) & CHAP (Challenge Handshake Protocol) & CHAP (Challenge Handshake Authentication Protocol)Authentication Protocol)
Institute of Technology Sligo - Dept of Computing
WAN TechnologiesWAN Technologies
Institute of Technology Sligo - Dept of Computing
WAN Technologies WAN Technologies OverviewOverview
Dedicated• T1, E1, T3, E3• xDSL• SONET
Analog• Dial-up modems• Cable modems• Wireless
Switched
Circuit Switched
• POTS• ISDN
Packet Switched
• X.25• Frame Relay
Cell Switched• ATM• SMDS
Institute of Technology Sligo - Dept of Computing
WAN Technologies WAN Technologies OverviewOverview
Dedicated• T1, E1, T3, E3• xDSL• SONET
Analog• Dial-up modems• Cable modems• Wireless
Switched
Circuit Switched
• POTS• ISDN
Packet Switched
• X.25• Frame Relay
Cell Switched• ATM• SMDS
Institute of Technology Sligo - Dept of Computing
Dedicated Digital ServicesDedicated Digital Services
T seriesT series in U.S. and in U.S. and E seriesE series in Europe in Europe Uses time division multiplexing to “slice up” Uses time division multiplexing to “slice up”
data and assign time slots for transmissionsdata and assign time slots for transmissions T1 = 1.544 MbpsT1 = 1.544 Mbps T3 = 44.736 MbpsT3 = 44.736 Mbps E1 = 2.048 MbpsE1 = 2.048 Mbps E3 = 34.368 MbpsE3 = 34.368 Mbps
•Uses twisted pair & fiber•Extremely popular•Moderate cost
Dedicated Digital Services provide full-time connectivity through a point-to-point link
Institute of Technology Sligo - Dept of Computing
Dedicated Digital ServicesDedicated Digital Services Digital Subscriber Lines (xDSL)Digital Subscriber Lines (xDSL);; the x stands the x stands
for a family of technologiesfor a family of technologies New WAN Technology for home use; decreasing New WAN Technology for home use; decreasing
bandwidth with increasing distance from the phone bandwidth with increasing distance from the phone companies CO.companies CO.
Data rates as high as 51.84 Mbps but more common Data rates as high as 51.84 Mbps but more common to be in the 100s of Kbpsto be in the 100s of Kbps
Varieties include HDSL, SDSL, ADSL, & VDSLVarieties include HDSL, SDSL, ADSL, & VDSL Moderate expense and getting cheaperModerate expense and getting cheaper
Institute of Technology Sligo - Dept of Computing
Dedicated Digital ServicesDedicated Digital Services Synchronous Optical NetworkSynchronous Optical Network (SONET) (SONET)
Specialized high bandwidth technology for use at Specialized high bandwidth technology for use at various Optical Carrier speeds (OC) ranging from various Optical Carrier speeds (OC) ranging from 51.84 Mbps (OC-1) to 9,952 Mbps (OC-192)51.84 Mbps (OC-1) to 9,952 Mbps (OC-192)
Uses lasers to divide the wavelength of the light into Uses lasers to divide the wavelength of the light into sections that can carry large amounts of data (Wave sections that can carry large amounts of data (Wave Division Multiplexing)Division Multiplexing)
Very expensive; used by large ISPs and other Internet Very expensive; used by large ISPs and other Internet backbone entities.backbone entities.
Institute of Technology Sligo - Dept of Computing
WAN Technologies WAN Technologies OverviewOverview
Dedicated• T1, E1, T3, E3• xDSL• SONET
Analog• Dial-up modems• Cable modems• Wireless
Switched
Circuit Switched
• POTS• ISDN
Packet Switched
• X.25• Frame Relay
Cell Switched• ATM• SMDS
Institute of Technology Sligo - Dept of Computing
Analog ServicesAnalog Services
Dial-up ModemsDial-up Modems (switched analog) (switched analog) Limited to 56 kbpsLimited to 56 kbps Works with existing phone networkWorks with existing phone network Low cost and widespread usage Low cost and widespread usage
Institute of Technology Sligo - Dept of Computing
Analog ServicesAnalog Services Cable ModemsCable Modems (Shared Analog) (Shared Analog)
Puts data signals on the same cable as television Puts data signals on the same cable as television signalssignals
Increasing in popularity Increasing in popularity Maximum bandwidth can be 10 Mbps, though this Maximum bandwidth can be 10 Mbps, though this
degrades as more users attach to a given network degrades as more users attach to a given network segment (behaving like an unswitched LAN)segment (behaving like an unswitched LAN)
Cost is relatively low; usage is small but increasing; Cost is relatively low; usage is small but increasing; the medium is coaxial cable. the medium is coaxial cable.
Institute of Technology Sligo - Dept of Computing
Analog ServicesAnalog Services
TerrestrialTerrestrial Bandwidths typically in Bandwidths typically in
the 11 Mbps range the 11 Mbps range Cost is relatively lowCost is relatively low Line-of-sight is usually Line-of-sight is usually
requiredrequired Usage is moderate Usage is moderate
SatelliteSatellite Can serve mobile Can serve mobile
users and remote users and remote usersusers
Usage is widespreadUsage is widespread Cost is very highCost is very high
Wireless
Institute of Technology Sligo - Dept of Computing
WAN Technologies WAN Technologies OverviewOverview
Dedicated• T1, E1, T3, E3• xDSL• SONET
Analog• Dial-up modems• Cable modems• Wireless
Switched
Circuit Switched
• POTS• ISDN
Packet Switched
• X.25• Frame Relay
Cell Switched• ATM• SMDS
Institute of Technology Sligo - Dept of Computing
Circuit Switched ServicesCircuit Switched Services
Plain Old Telephone SystemPlain Old Telephone System (POTS) (POTS) NotNot a computer data service but... a computer data service but...
POTS is an important component of our POTS is an important component of our communication infrastructure andcommunication infrastructure and
It is still the standard for designing reliable It is still the standard for designing reliable networksnetworks
Institute of Technology Sligo - Dept of Computing
Circuit Switched ServicesCircuit Switched Services Integrated Services Digital NetworkIntegrated Services Digital Network
(ISDN)(ISDN) Historically important--first dial-up digital Historically important--first dial-up digital
serviceservice Cost is moderate; max. bandwidth = 128 kbps Cost is moderate; max. bandwidth = 128 kbps
for BRI (Basic Rate Interface)for BRI (Basic Rate Interface) 2 B channels @ 64kps and 1 D channel @ 16kps2 B channels @ 64kps and 1 D channel @ 16kps B channels are voice/data channels; D for B channels are voice/data channels; D for
signalingsignalingB
B
D
Institute of Technology Sligo - Dept of Computing
WAN Technologies WAN Technologies OverviewOverview
Dedicated• T1, E1, T3, E3• xDSL• SONET
Analog• Dial-up modems• Cable modems• Wireless
Switched
Circuit Switched
• POTS• ISDN
Packet Switched
• X.25• Frame Relay
Cell Switched• ATM• SMDS
Institute of Technology Sligo - Dept of Computing
Packet Switched ServicesPacket Switched Services X.25X.25 (Connection-oriented) (Connection-oriented)
Older WAN technology developed in 1970sOlder WAN technology developed in 1970s ReliableReliable--X.25 has been extensively debugged and is --X.25 has been extensively debugged and is
now very stable--literally no errors in modern X.25 now very stable--literally no errors in modern X.25 networksnetworks
Store & ForwardStore & Forward--Since X.25 stores the whole frame --Since X.25 stores the whole frame to error check it before forwarding it on to the to error check it before forwarding it on to the destination, it has an inherent delay (unlike Frame destination, it has an inherent delay (unlike Frame Relay) and requires large, expensive memory Relay) and requires large, expensive memory buffering capabilities.buffering capabilities.
Institute of Technology Sligo - Dept of Computing
Packet Switched ServicesPacket Switched Services Frame RelayFrame Relay (Connectionless) (Connectionless)
More efficient and much faster than X.25More efficient and much faster than X.25 Packet switched version of ISDN (which is circuit Packet switched version of ISDN (which is circuit
switched); data rates up to 44.736Mbps with 56kbps switched); data rates up to 44.736Mbps with 56kbps and 384kbps being the most popularand 384kbps being the most popular
Used mostly to forward LAN IP and IPX packets but Used mostly to forward LAN IP and IPX packets but can be used to forward other types of trafficcan be used to forward other types of traffic
Primary competitive advantage is its low costPrimary competitive advantage is its low cost
Institute of Technology Sligo - Dept of Computing
WAN Technologies WAN Technologies OverviewOverview
Dedicated• T1, E1, T3, E3• xDSL• SONET
Analog• Dial-up modems• Cable modems• Wireless
Switched
Circuit Switched
• POTS• ISDN
Packet Switched
• X.25• Frame Relay
Cell Switched• ATM• SMDS
Institute of Technology Sligo - Dept of Computing
Cell Switched ServicesCell Switched Services Asynchronous Transfer ModeAsynchronous Transfer Mode (ATM) (ATM)
Relatively new WAN Technology related to Relatively new WAN Technology related to broadband ISDN; max. bandwidth = 622 Mbpsbroadband ISDN; max. bandwidth = 622 Mbps
Developed in order to provide one technology for Developed in order to provide one technology for both WANs and LANs to transport data, video, and both WANs and LANs to transport data, video, and voice. (High Cost)voice. (High Cost)
Key Benefits:Key Benefits: One network for all traffic--voice, data, videoOne network for all traffic--voice, data, video Compatible with current wiring infrastructure (cable plant)Compatible with current wiring infrastructure (cable plant) Very flexible and scalableVery flexible and scalable Simplifies network managementSimplifies network management
Institute of Technology Sligo - Dept of Computing
Cell Switched ServicesCell Switched Services
Switched Multimegabit Data ServiceSwitched Multimegabit Data Service (SMDS)(SMDS) Closely related to ATM; SMDS is the MAN Closely related to ATM; SMDS is the MAN
(Metropolitan Area Network) implementation (Metropolitan Area Network) implementation of ATMof ATM
High Cost with max. bandwidth 44.736 MbpsHigh Cost with max. bandwidth 44.736 Mbps
Institute of Technology Sligo - Dept of Computing
Acronym Name Max. Bandwidth Comments
T1, T3 T1, T3 1.544 & 44.736 Mbps Widely used telecommunicationsxDSL Digital Subscriber Line 384 kbps New technology over phone lines
SONETSynchronous Optical Network
9,992 Mbps Very fast optical fiber transmission
Dial-up Modem Modem 56 kbps Mature technology over phone lines
Cable Modem Cable Modem 10 Mbps New technology using cable TV
Terrestrial Wireless Wireless 11 Mbps Microwave and laser links
Satellite Wireless Wireless 2 Mbps Microwave and laser links
POTSPlain Old Telephone Service
4 kHz Analog The Standard for Reliability
ISDNIntegrated Services Digital Network
128 kbps Data and Voice Together
X.25 X.25 An Old Reliable, WorkhorseFrame Relay Frame Relay up to 44.736 Mbps A flexible new workhorse; son of ISDN
ATMAsynchronous Transfer Mode
622 Mbps High powered Networks
SMDSSwitched Multimegabit Data Service
1.544 & 44.736 Mbps MAN variant of ATM
Cell Switched Services
Dedicated Digital Services
Analog Services
Circuit Switched Services
Packet Switched Services
WAN Technologies Review
Institute of Technology Sligo - Dept of Computing
Router BasicsRouter Basics
Institute of Technology Sligo - Dept of Computing
Internal ComponentsInternal Components
RAM NVRAM Flash ROM
InterfacesConsoleAuxiliary
Institute of Technology Sligo - Dept of Computing
RAMRAM Temporary storage for router configuration filesTemporary storage for router configuration files RAM content is lost on power down or restartRAM content is lost on power down or restart Stores...Stores...
Routing tablesRouting tables ARP cacheARP cache Fast switching cacheFast switching cache Packet bufferingPacket buffering And Packet hold queuesAnd Packet hold queues
Institute of Technology Sligo - Dept of Computing
NVRAMNVRAM
Non-volatile RAMNon-volatile RAM Stores backup/startup configuration filesStores backup/startup configuration files Content is Content is notnot lost when router is powered lost when router is powered
down or restarted.down or restarted.
Institute of Technology Sligo - Dept of Computing
FlashFlash EEPROM (Electronically Erasable EEPROM (Electronically Erasable
Programmable Read-Only Memory)Programmable Read-Only Memory) Holds the Cisco IOS (Internet Operating Holds the Cisco IOS (Internet Operating
System)System) Allows updating of software without Allows updating of software without
replacing the Flash chipreplacing the Flash chip Multiple versions of IOS can be storedMultiple versions of IOS can be stored Retained on power downRetained on power down
Institute of Technology Sligo - Dept of Computing
ROMROM
Contains POST (Power On Self Test)Contains POST (Power On Self Test) A bootstrap program (loads the Cisco IOS)A bootstrap program (loads the Cisco IOS) And operating system softwareAnd operating system software
Backup, trimmed down version of the IOSBackup, trimmed down version of the IOS Upgrades require installing new chip setUpgrades require installing new chip set
Institute of Technology Sligo - Dept of Computing
InterfacesInterfaces
Network connections through which Network connections through which packets enter and exit the routerpackets enter and exit the router
Attached to the motherboard or as Attached to the motherboard or as separate modules.separate modules.
Institute of Technology Sligo - Dept of Computing
LabsLabs
Before moving on to Ch. 3, make sure you Before moving on to Ch. 3, make sure you have done both of the required labs for have done both of the required labs for Ch. 2Ch. 2 Lab 2.2.2Lab 2.2.2 Lab 2.2.3.2Lab 2.2.3.2
Institute of Technology Sligo - Dept of Computing
Router User InterfaceRouter User Interface
Institute of Technology Sligo - Dept of Computing
User EXEC ModesUser EXEC Modes User modeUser mode
Limited mode used for checking the routers status, Limited mode used for checking the routers status, looking at routing tables, etc.looking at routing tables, etc.
You You cannotcannot configure the router configure the router Once you’ve typed the password to enter user mode, Once you’ve typed the password to enter user mode,
you will see the > prompt. The word “Router” will be you will see the > prompt. The word “Router” will be the name of the router.the name of the router.
Password:Password:RouterRouter>> Means you’re in
user mode
Institute of Technology Sligo - Dept of Computing
Privileged EXEC ModesPrivileged EXEC Modes Privileged modePrivileged mode
Does everything User mode doesDoes everything User mode does Full power to configure the routerFull power to configure the router In user mode, you enter the command In user mode, you enter the command
“enable” and then the privileged password“enable” and then the privileged password
Router> enableRouter> enablePassword:Password:RouterRouter## Means you’re in
privileged mode
Institute of Technology Sligo - Dept of Computing
Command ListsCommand Lists To get a list of commands available in either To get a list of commands available in either
user mode or privileged mode, enter a user mode or privileged mode, enter a ?? at the at the prompt.prompt.
Router> ?Router> ?Router# ?Router# ? Since the available commands will be more than Since the available commands will be more than
the screen can hold, you will get the the screen can hold, you will get the --More----More-- message at the bottom.message at the bottom.
Hitting the Hitting the space barspace bar will advance the screen to will advance the screen to show the next page.show the next page.
Institute of Technology Sligo - Dept of Computing
ipflash:interfacesipxversionparser
Router# show ?
Getting Help on a CommandGetting Help on a Command The ? can be used with a partial command to learn all the The ? can be used with a partial command to learn all the
available commands that match what you entered.available commands that match what you entered. To use this help feature, enter the partial command, then To use this help feature, enter the partial command, then
tap the tap the space barspace bar, then type , then type ?? For example...For example...
The Router returned all the available commands
for “show”
Institute of Technology Sligo - Dept of Computing
Error IndicatorError Indicator When you’ve entered an error in the When you’ve entered an error in the
command string, a carat (command string, a carat (^̂) symbol will ) symbol will indicate where the error occurred.indicate where the error occurred.
For example...For example...
Router# show runing-config ^% Invalid input detected at the ‘^’ marker
Institute of Technology Sligo - Dept of Computing
LabsLabs
Before taking the Ch. 2/3 test, make sure Before taking the Ch. 2/3 test, make sure you have done both of the required labs you have done both of the required labs for Ch. 3for Ch. 3 Lab 3.2.1Lab 3.2.1 Lab 3.2.2Lab 3.2.2