Chapter 2 – Sections & Objectives

2.1 IOS Bootcamp

• Explain the purpose of Cisco IOS.
• Explain how to access a Cisco IOS device for configuration purposes.
• Explain how to navigate Cisco IOS to configure network devices.
• Describe the command structure of Cisco IOS software.

2.2 Basic Device Configuration

• Configure hostnames on a Cisco IOS device using the CLI.
• Use Cisco IOS commands to limit access to device configurations.
• Use IOS commands to save the running configuration.

2.3 Address Schemes

• Explain how devices communicate across network media.
• Configure a host device with an IP address.
• Verify connectivity between two end devices.

2.1 IOS Bootcamp

Cisco IOS

• • Operating Systems
    • PC OS allows users to interact with the computer
    • User-computer interaction in PC OSs are often done via mouse, keyboard and monitor
    • Cisco IOS is also an Operating System
    • Cisco IOS allows users to interact with Cisco devices.

• Cisco IOS enables a technician to:
  • Use a keyboard to run CLI-based network programs.
  • Use a keyboard to enter text and text-based commands.
  • View output on a monitor.
• All Cisco networking devices come with a default IOS.
• It is possible to upgrade the IOS version or feature set.

Cisco IOS Access

• Access Methods
  • Console
  • Auxiliar
  • Virtual Terminal (Telnet / SSH)
• Terminal Emulation Programs
  • PuTTY
  • Tera Term
  • SecureCRT

Navigate the IOS

• • Cisco IOS Modes of Operation
    • Initial configuration must be done via console connection.
    • Configuration is then done via various CLI command modes.

• Primary Command Modes
  • User EXEC Mode
  • Privileged EXEC Mode
• Configuration Command Modes
  • The Configure Terminal command enters the Global Configuration Mode.
  • Sub-configuration modes are accessible from the Privileged EXEC Mode.
  • Examples are: swtich(config-line)# and switch(config-if)#
• Navigate Between IOS Modes
  • Navigation between modes is also done via commands.
  • The enable command enters the Privileged EXEC Mode.
  • The exit commands exits to the parent command mode.

The Command Structure

• Basic IOS Command Structure
  • The general syntax for a command is the command followed by any appropriate keywords and arguments.
  • Keyword – a specific parameter defined in the operating system
  • Argument – not predefined; a value or variable defined by the user
• IOS Command Syntax
  • Provides the pattern or format that must be used when entering a command.
  • The Cisco IOS Command Reference is the ultimate source of information for a particular IOS command.
• IOS Help Feature
  • The IOS has two forms of help available: Context-Sensitive Help and Command Syntax Check.
• Hotkeys and Shortcuts
  • Commands and keywords can be shortened to the minimum number of characters that identify a unique selection.
  • Line editing keyboard shortcuts such as Ctrl-A are also supported.

2.2 Basic Device Configuration

Hostnames

• Device Names
  • Hostnames allow devices to be identified by network administrators over a network or the Internet.
  • Very important and should also be displayed in the topology.
• Configure Hostnames
  • IOS hostnames should:
  • Start with a letter
  • Contain no spaces
  • End with letter or digit
  • Use only letters, digits or dashes
  • Be less than 64 characters in length

Limit Access to Device Configurations

• Secure Device Access
  • Secure privileged EXEC and user EXEC access with a password.
  • Secure virtual terminal lines with a password.
• Configure Passwords
  • Use strong passwords.
  • Avoid re-using passwords
• Encrypt Passwords
  • Cisco IOS displays passwords in plain text by default.
  • Passwords should be encrypted.
• Banner Messages
  • Important part of the legal process in the event that someone is prosecuted for breaking into a device.
  • Wording that implies that a login is “welcome” or “invited” is not appropriate.
  • Often used for legal notification because it is displayed to all connected terminals.

Save Configurations

• Save the Running Configuration File
  • File stored in NVRAM that contains all of the commands that will be used upon startup or reboot
  • NVRAM does not lose its contents when the device is powered off.
• Alter the Running Configuration
  • File stored in RAM that reflects the current configuration, modifying affects the operation of a Cisco device immediately.
  • RAM loses all of its content when the device is powered off or restarted.
• Capture Configuration to a Text File
  • Configuration files can also be saved and archived to a text document.
  • The configuration can then be edited with any text editor and placed back in the device.

2.3 Address Schemes

Ports and Addresses

• IP Addresses
  • Each end device on a network must be configured with an IP address.
  • Enable devices to establish end-to-end communication on the Internet.
  • The structure of an IPv4 address is called dotted decimal notation and is represented by four decimal numbers between 0 and 255.
  • IPv6 is the most recent version of IP and the replacement for the more common IPv4.
• Interface and Ports
  • Network communications depend on interfaces and the cables that connect them.
  • Different types of network media have different features and benefits.
  • Ethernet is the most common local area network (LAN) technology.
  • SVI provides a means to remotely manage a switch over a network.

Configure IP Addressing

• Manual IP Address Configuration for End Devices
  • To manually configure an IPv4 address on a Windows host, open the Control Panel > Network Sharing Center > Change adapter settings and choose the adapter.
  • Next right-click and select Properties to display the Local Area Connection Properties shown in Figure 1.
• Automatic IP Address Configuration for End Devices
  • DHCP enables automatic IPv4 address configuration for every end device that has DHCP enabled. No extra configuration is needed.
• Switch Virtual Interface Configuration
  • To configure an SVI on a switch, use the interface vlan 1 global configuration command. Vlan 1 is not an actual physical interface but a virtual one.

Verifying Connectivity

• • Interface Addressing Verification
    • Cisco IOS supports commands to allow IP configuration verification.

• End-To-End Connectivity Test
  • The ping command can be used to test connectivity to another device on the network or a website on the Internet.

2.4 Chapter Summary

Summary

• Explain the features and functions of Cisco IOS Software.
• Configure initial settings on a network device using the Cisco IOS software.
• Given an IP addressing scheme, configure IP address parameters on end devices to provide end-to-end connectivity in a small to medium-sized business network.

Section 2.1 New Terms and Commands

Section 2.2 New Terms and Commands

Section 2.3 New Terms and Commands

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