Chapter 6: Router and IOS Basics

1
CCNA Guide to Cisco Networking

• Chapter 6 Router and IOS Basics

2
Objectives

• Describe the benefits of network segmentation
  with routers
• Understand the elements of the Cisco router user
  interface
• Configure the HyperTerminal program to interface
  with the Cisco router
• Describe the various router configuration modes
• Describe the various router passwords

3
Objectives (continued)

• Understand the enhanced editing features of the
  Cisco IOS
• Understand the elements of the Cisco switch user
  interface
• Compare router components to typical PC
  components

4
Benefits Of Routing

• Packet filtering
• Traffic control
• Connect LANs
• WAN connections
• Segmentation

5
Cisco Router User Interface

• Cisco Internetwork Operating System (IOS)
• Command-line interface (CLI)
• Command executive or EXEC
• Router access
• Console port (console)
• Rollover cable, RJ-45 to DB-9, RJ-45 to DB-25
• Auxiliary port (AUX)
• Virtual terminal (VTY)

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Cisco Router User Interface (continued)
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Cisco Router User Interface (continued)
8
Connecting Via Terminal Programs

• Establish a connection
• Physical connection through console
• 9600 bits per second, data bits 8, stop bits 1,
  parity none, flow control none
• Logical connection through VTY
• Terminal programs
• HyperTerminal, Microphone Pro, ProComm Plus,
  Telix, Tera Term

9
System Configuration Dialog

• Router enters system configuration dialog
• No previous configuration (factory default)
• Start-up file has been erased
• Registry setting has is set to 0x2142
• Forced by entering the CLI setup command
• Default options are in brackets
• Two types of setup
• Basic management setup
• Extended setup

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System Configuration Dialog (continued)
11
User Interface

• Return or Enter key to reach the prompt when
  connecting with a terminal program
• Initial prompt consists of two parts
• Hostname
• Greater than symbol (gt)
• User EXEC mode or user mode
• View basic settings and monitoring
• Question mark (?)
• Context-sensitive help

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User Interface (continued)

• Privileged EXEC mode or Exec mode
• enable command at user prompt
• May be prompted for a password
• Exec mode prompt consists of two parts
• Hostname
• Pound sign symbol (gt)
• Exec mode commands that can will affect router
  operations
• Setup
• Copy
• Erase

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User Interface (continued)
14
Configuration Modes

• Global configuration mode
• Router(config)
• Interface mode
• Router(configif)
• Line configuration mode
• Router(config-line)
• Router configuration mode
• Router(config-router)

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Configuration Modes (continued)
16
Configuration Modes (continued)

• exit command
• CrtlZ
• Incorrect character symbol ()
• Command shortcuts
• Example show running-config or sh ru

17
Configuration Modes (continued)
18
Plethora Of Passwords

• Routers have five basic passwords and several
  advanced passwords
• Enable password
• Enable secret password
• Virtual terminal password
• Console password
• AUX password
• Three of the five passwords can be setup during
  initial configuration dialog
• service-password encryption command

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Plethora Of Passwords (continued)
20
Plethora Of Passwords (continued)
21
Plethora Of Passwords (continued)
22
Plethora Of Passwords (continued)
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Plethora Of Passwords (continued)
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Plethora Of Passwords (continued)
25
Enhanced Editing
26
Command History

• Retrieve previously typed commands
• Stores up 10 previously typed commands by default
• Up arrow (CtrlP)
• Down arrow (CtrlN)
• Tab key to complete commands
• terminal history command
• 0 through 256

27
Configuring Router Identification

• Configure router host name
• Router(config) hostname
• Message of the day login banner
• Delimiting character
• banner motd .... command
• Interface description
• description command

28
Configuring Router Identification (continued)
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Configuring Router Identification (continued)
30
Configuring Router Identification (continued)
31
Configuring The Time And Date

• Configure the time in enable mode with the clock
  set command
• Universal Time Code
• Greenwich, United Kingdom
• Configure the time zone in global configuration
  mode
• show clock command

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Configuring The Time And Date (continued)
33
Switch User Interface

• Two types of operating systems
• IOS-based
• 1900, 2820, and 2900 switches
• Set-based
• 1984G, 2926, 4000, 5000, and 6000 switches
• Catalyst 1900 menu
• M Menus
• K Command Line
• I IP Configuration
• Modes and passwords
• Setting the host name

34
Router Components

• ROM
• Flash memory
• NVRAM
• RAM/DRAM
• Interfaces

35
Router Components (continued)

• ROM
• Read-only memory (ROM)
• Bootstrap program
• ROM monitor firmware
• ROM monitor mode
• (gt) or (rommon 1gt)

36
Router Components (continued)

• Flash memory
• Erasable, programmable, read-only memory (EPROM)
• Contains the Cisco IOS
• Can store multiple IOS
• show version command
• show flash command

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Router Components (continued)

• NVRAM
• Nonvolatile random access memory (NVRAM)
• Special type of RAM
• Not cleared when router is rebooted
• Startup configuration file
• show start command

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Router Components (continued)

• Random access memory (RAM)
• Volatile
• Information is not retain during router reboot
• Running configuration
• show running-config command
• show memory command
• show buffers command

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Router Components (continued)

• Interfaces
• Token Ring
• Basic Rate Interface (BRI)
• Asynchronous Transfer Mode (ATM)
• Fiber Distributed Data Interface (FDDI)
• Channel Interface Processor (CIP) for System
  Network Architecture (SNA)
• High-Speed Serial Interface (HSSI)

40
Summary

• Cisco routers use the Cisco IOS to provide an
  interface for network operators and
  administrators
• The first mode entered is user EXEC (routergt
  prompt) and the next mode is privileged EXEC
  (router prompt)
• In user EXEC, you can accomplish basic tasks such
  as checking the router status, checking
  connectivity, and viewing some configuration
  information
• To actually configure the router, privileged EXEC
  mode must be accessed, as this mode leads to the
  two most common modes for router configuration
  global configuration mode and interface
  configuration mode
• The privileged EXEC mode is often called enable
  mode because it is entered using the enable
  command

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Summary (continued)

• The enable, enable secret, and VTY passwords are
  set during initial configuration if the system
  configuration dialog is used, but they can also
  be added and changed in global configuration mode
  (router(config) prompt)
• When configured, the enable secret password
  supersedes the enable password
• This is because the enable secret is an encrypted
  password that is not viewable in the
  configuration file, which means that it has less
  chance of being compromised
• For this reason, it should be different from the
  enable password

42
Summary (continued)

• The Cisco 1900 switch allows configuration from a
  command line just like a Cisco router
• Host names and passwords, as well as other
  parameters, are configured on the Cisco 1900
  switch in much the same way as they are
  configured on a router
• The components of a router include ROM, flash
  memory, NVRAM, RAM/DRAM, and interfaces
• ROM stores a limited version of the Cisco IOS and
  routines for checking the hardware during system
  boot
• It is responsible for initializing the router

43
Summary (continued)

• Flash memory stores the Cisco IOS that is loaded
  by default during system boot
• NVRAM stores the startup copy of the router
  configuration file that is loaded by default
  during system boot
• RAM/DRAM stores the working copy (running
  configuration) of the router configuration
• This configuration is loaded into RAM from NVRAM
  by default during bootup
• It is erased if the router is rebooted, unless it
  is saved to the startup configuration