Transcript Routers - Telenet Service

Routers
• A router is a computer
• Computers have four basic components:
–
–
–
–
a CPU,
memory,
interfaces, and
a bus
• The router is a computer that selects the
best paths, and manages the switching of
packets between two different networks
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Cisco Routers
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Router - internal components
• RAM/DRAM
– Stores routing tables, ARP cache, fast-switching
cache, packet buffering (shared RAM), and
packet hold queues.
– also provides temporary and/or running
memory for the router’s configuration file while
the router is powered on.
– RAM content is lost when you power down or
restart.
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Router - internal components
• NVRAM
– non-volatile RAM
– stores a router’s backup/start-up configuration
file;
– content remains when you power down or
restart
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Router - internal components
• Flash
– erasable, reprogrammable ROM
– holds the operating system image and
microcode
– allows you to update software without
removing and replacing chips on the processor
– content remains when you power down or
restart
– multiple versions of IOS software can be stored
in Flash memory
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Router - internal components
• ROM
– contains power-on diagnostics,
– a bootstrap program, and
– operating system software
– software upgrades in ROM require replacing
pluggable chips on the CPU
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Router - internal components
• Interface
– network connection through which packets
enter and exit a router
– it can be on the motherboard or on a separate
interface module
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Routing
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Router Configuration
• A router is made up of configurable
components.
• A router has modes
–examining,
–maintaining, and
–changing the components.
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Router Configuration
• show commands are used for examination.
• You use cdp to show entries about
neighbours.
• You access other routers by using telnet.
• You test network connectivity layer by
layer.
• Testing commands include ping, trace, telnet, and
debug
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Router Configuration
• A router can be configured from many locations:
 Upon initial installation, it is configured from the
console terminal. The console terminal is a computer
connected to the router through the console port.
 It can be connected via modem by using the
auxiliary port.
 After it is installed on the network, it can be
configured from Virtual Terminals 0 through 4.
• Files can also be downloaded from a TFTP server
on the network
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Router Modes
• Whether accessed from the console or by a
Telnet session through a TTY port, the router
can be placed in several modes.
• Each mode provides different functions:
– User EXEC mode
– Privileged EXEC mode
– Set-up mode
– Global configuration mode
– Other configuration modes
– RXBOOT mode
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Router Modes
 User EXEC mode
 A “look-only” mode in which the user can view
some information about the router, but cannot
change anything.
 Privileged EXEC mode
 Supports the debugging and testing commands,
detailed examination of the router, manipulation of
configuration files, and access to configuration
modes.
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Router Modes
 Set-up mode
 Presents an interactive prompted dialog at the
console that helps the new user create a first-time
basic configuration.
 Global configuration mode
• Implements powerful one-line commands that
perform simple configuration tasks.
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Router Modes
 Other configuration modes
 Provide more detailed multiple-line
configurations.
 RXBOOT mode
– A maintenance mode that can be used, among
other things, to recover lost passwords.
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Router Status Commands
 show version
 Displays the configuration of the system
hardware,
 the software version,
 the names and sources of configuration files,
and
 the boot image.
 show processes
 Displays information about the active
processes.
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Router Status Commands
 show protocols
 Displays the configured protocols.
 This command shows the status of all
configured Layer 3 protocols.
 show mem
 Shows statistics about the router’s memory,
including memory free pool statistics.
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Router Status Commands
 show stacks
 Monitors the stack use of processes and
interrupt routines and displays the reason for
the last system reboot.
 show buffers
 Provides statistics for the buffer pools on the
router.
 show flash
 Shows information about the Flash memory
device.
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Router Status Commands
 show running-config
 Displays the active configuration file.
 show startup-config
 Displays the backup configuration file.
 show interfaces
– Displays statistics for all interfaces configured
on the router.
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Cisco Discovery Protocol
(CDP)
• CDP provides a single proprietary
command that enables network
administrators to access a summary of
what the configurations look like on
other directly connected routers.
• CDP runs over a data link layer connecting
lower physical media and upper-networklayer protocols.
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CDP
• Because CDP operates at this level, CDP
devices that support different network-layer
protocols can learn about each other.
• CDP starts up automatically at boot up.
CDP can then automatically discover
neighbouring Cisco devices running CDP.
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CDP
• Discovered devices extend beyond those
having TCP/IP.
• CDP discovers directly connected Cisco
devices regardless of which Layer 3 and 4
protocol suite they run.
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CDP
• CDP provides information about each CDP neighbour
device. Values include the following:
 Device identifiers—For example, the router’s configured
host name and domain name (if any)
 Address list—At least one address for SNMP, up to one
address for each protocol supported
 Port identifier—Such as Ethernet 0, Ethernet 1, and Serial
0
 Capabilities list—If, for example, the device acts as a source
route bridge as well as a router
 Version—Information such as that provided by the local
command show version
• Platform—The device’s hardware platform; for example,
Cisco 7000
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Cisco Router Configuration
• We have seen
– show and
– cdp commands
• show startup-config - display the backup
configuration file
• show running-config—display active
configuration file.
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Cisco Router Configuration
• erase startup-config - deletes the backup
configuration file in NVRAM.
• reload - reloads the router, causing it to run
through the entire configuration process.
• Setup - to enter setup mode from the
privileged EXEC prompt.
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Cisco Router Configuration
• configure terminal—Configures manually
from the console terminal.
• copy tftp running-config—Loads
configuration information from a network
TFTP server.
• copy running-config startup-config—
Stores the current configuration from RAM
into NVRAM.
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Cisco Router Configuration
• copy running-config tftp — Stores the
current configuration from RAM on a
network TFTP server.
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Cisco Router Configuration
Router> enable
password:
Router# configure terminal
Router(config)# [configure mode command]
• e.g. interface, subinterface, controller, line,
router etc.
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Cisco Router Configuration
• Specific configuration modes:
– interface mode - for configuring interfaces
– subinterface mode - for configuring multiple
virtual interfaces on a single physical interface
– line mode - for configuring the operation of a
terminal line
– router mode - for configuring an IP routing
protocol
– etc.
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Cisco Router Configuration
• Configuring router identification
Router# config term
Router(config)# hostname LABA
LABA#
ctrl-z : back to privileged exec mode
exit : back out one level
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Cisco Router Configuration
• Message of the day banner
LABA(config)#banner motd # message #
• Interface description
LABA(config)#interface ethernet 0
LABA(config-if)#description my LAN, BG
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Password configuration
• Console password
• Virtual terminal password
• Privileged exec password
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Console password
LABA(config)#line console 0
LABA(config-line)#login
LABA(config-line)#password cisco
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Virtual Terminal password
LABA(config)#line vty 0 4
LABA(config-line)#login
LABA(config-line)#password cisco
• Enable Password
LABA(config)#enable password class
or prefer
LABA(config)#enable secret class
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Configuring interfaces
LABA(config)#int s 0
LABA(config-if)#clock rate 56000
• clk rate is set for DCEs
LABA(config-if)#bandwidth 56
• no clock rate removes clock rate
• shut down/no shut down
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Configuring routing protocols
LABA(config)#router rip
LABA(config-router)#network 1.0.0.0
LABA(config-router)# network 2.0.0.0
LABA(config-router)#ctrl-z
LABA(config)#ctrl-z
LABA#show ip protocol
LABA#show ip route [routing table]
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Configuring routing protocols
LABA>show ip interfaces
LABA#debug ip rip
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Exercise - Configuring LABA
• Hostname:
Router>ena
password:
Router#config term
Router(config)#hostname lab-a
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Exercise - Configuring LABA
• Enable secret password - class
lab-a(config)#enable secret class
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Exercise - Configuring LABA
• All appropriate interfaces with IP addresses
and subnet masks
lab-a(config)#int s 0
lab-a(config-if)#ip address 201.100.11.1
255.255.255.0
lab-a(config-if)#clockrate 56000
lab-a(config-if)#bandwidth 56
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Exercise - Configuring LABA
lab-a(config)#int e 0
lab-a(config-if)#ip address 192.5.5.1
255.255.255.0
lab-a(config-if)#bandwidth 56
lab-a(config)#int e 1
lab-a(config-if)#ip address 205.7.5.1
255.255.255.0
lab-a(config-if)#bandwidth 56
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Exercise - Configuring LABA
• Configure rip
lab-a(config)#router rip
lab-a(config)#network 205.7.5.0
lab-a(config)# network 192.5.5.0
lab-a(config)# network 201.100.11.0
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Exercise - Configuring LABA
• Console login password - cisco
lab-a(config)#line console 0
lab-a(config-line)#login
lab-a(config-line)#password cisco
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Exercise - Configuring LABA
• Vty login password - cisco
lab-a(config)#line vty 0 4
lab-a(config-line)#login
lab-a(config-line)#password cisco
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