Cisco Networking Module 2 PDF
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This document is Module 2 of an Introduction to Networks course by Cisco, it provides information about the basics of network device configuration, including switch configuration. Topics include console access, access methods, IP addressing and IOS navigation.
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Module 2: Basic Switch and End Device Configuration Introductions to Networks v7.0 (ITN) INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES...
Module 2: Basic Switch and End Device Configuration Introductions to Networks v7.0 (ITN) INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Module Objectives Module Title: Basic Switch and End Device Configuration Module Objective: Implement initial settings including passwords, IP addressing, and default gateway parameters on a network switch and end devices. Topic Title Topic Objective Explain how to access a Cisco IOS device for configuration Cisco IOS Access purposes. Explain how to navigate Cisco IOS to configure network IOS Navigation devices. The Command Structure Describe the command structure of Cisco IOS software. Basic Device Configuration Configure a Cisco IOS device using CLI. Save Configurations Use IOS commands to save the running configuration. Ports and Addresses Explain how devices communicate across network media. Configure IP Addressing Configure a host device with an IP address. Verify Connectivity Verify connectivity between two end devices. 2.1 Cisco IOS Access © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 3 INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Cisco IOS Access Operating Systems Shell - The user interface that allows users to request specific tasks from the computer. These requests can be made either through the CLI or GUI interfaces. Kernel - Communicates between the hardware and software of a computer and manages how hardware resources are used to meet software requirements. Hardware - The physical part of a computer including underlying electronics. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Cisco IOS Access GUI A GUI allows the user to interact with the system using an environment of graphical icons, menus, and windows. A GUI is more user-friendly and requires less knowledge of the underlying command structure that controls the system. Examples of these are: Windows, macOS, Linux KDE, Apple iOS and Android. GUIs can fail, crash, or simply not operate as specified. For these reasons, network devices are typically accessed through a CLI. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Cisco IOS Access Purpose of an OS PC operating system enables a user to do the CLI-based network operating system enables a following: network technician to do the following: Use a mouse to make Use a keyboard to run CLI-based selections and run programs network programs Enter text and text-based commands Use a keyboard to enter text and View output on a monitor text-based commands View output on a monitor INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Cisco IOS Access Access Methods Console – A physical management port used to access a device in order to provide maintenance, such as performing the initial configurations. Secure Shell (SSH) – Establishes a secure remote CLI connection to a device, through a virtual interface, over a network. (Note: This is the recommended method for remotely connecting to a device.) Telnet – Establishes an insecure remote CLI connection to a device over the network. (Note: User authentication, passwords and commands are sent over the network in plaintext.) INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Cisco IOS Access Terminal Emulation Programs Terminal emulation programs are used to connect to a network device by either a console port or by an SSH/Telnet connection. There are several terminal emulation programs to chose from such as PuTTY, Tera Term and SecureCRT. 2.2 IOS Navigation © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 9 INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES IOS Navigation Primary Command Modes User EXEC Mode: Allows access to only a limited number of basic monitoring commands Identified by the CLI prompt that ends with the > symbol Privileged EXEC Mode: Allows access to all commands and features Identified by the CLI prompt that ends with the # symbol INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES IOS Navigation Configuration Mode and Subconfiguration Modes Global Configuration Mode: Used to access configuration options on the device Line Configuration Mode: Used to configure console, SSH, Telnet or AUX access Interface Configuration Mode: Used to configure a switch port or router interface IOS Navigation NavigationCOLLEGE Between INSTITUTE IOS OFOF Modes ANDAND INFORMATION INFORMATION COMPUTING COMPUTING SCIENCES SCIENCES ▪ Privileged EXEC Mode: To move from user EXEC mode to privilege EXEC mode, use the enabled command. ▪ Global Configuration Mode: To move in and out of global configuration mode, use the configure terminal command. To return to privilege EXEC mode, use the exit command. ▪ Line Configuration Mode: To move in and out of line configuration mode, use the line command followed by the management line type. To return to global configuration mode, use the exit command. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES IOS Navigation Navigation Between IOS Modes (Cont.) Subconfiguration Modes: To move out of any subconfiguration mode to get back to global configuration mode, use the exit command. To return to privilege EXEC mode, use the end command or key combination Ctrl +Z. To move directly from one subconfiguration mode to another, type in the desired subconfiguration mode command. In the example, the command prompt changes from (config-line)# to (config-if)#. 2.3 The Command Structure © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 14 INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES The Command Structure Basic IOS Command Structure Keyword – This is a specific parameter defined in the operating system (in the figure, ip protocols). Argument - This is not predefined; it is a value or variable defined by the user (in the figure, 192.168.10.5). INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES The Command Structure IOS Command Syntax Check A command might require one or more arguments. To determine the keywords and arguments required for a command, refer to the command syntax. Boldface text indicates commands and keywords that are entered as shown. Italic text indicates an argument for which the user provides the value. Convention Description boldface Boldface text indicates commands and keywords that you enter literally as shown. italics Italic text indicates arguments for which you supply values. [x] Square brackets indicate an optional element (keyword or argument). {x} Braces indicate a required element (keyword or argument). Braces and vertical lines within square brackets indicate a required choice within an [x {y | z }] optional element. Spaces are used to clearly delineate parts of the command. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES The Command Structure IOS Command Syntax Check (Cont.) ▪ The command syntax provides the pattern, or format, that must be used when entering a command. ▪ The command is ping and the user- defined argument is the ip-address of the destination device. For Structure The Command example, ping 10.10.10.5. IOS Command Syntax Check (Cont.) ▪ The command is traceroute and the user-defined argument is the ip- address of the destination device. For example, traceroute 192.168.254.254. ▪ If a command is complex with multiple arguments, you may see it represented like this: INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES The Command Structure IOS Help Features The IOS has two forms of help available: context-sensitive help and command syntax check. Context-sensitive help enables you to Command syntax check verifies that a quickly find answers to these questions: valid command was entered by the user. Which commands are available in each command mode? If the interpreter cannot understand Which commands start with specific the command being entered, it will characters or group of characters? provide feedback describing what is wrong with the command. Which arguments and keywords are available to particular commands? The Command Structure Hot Keys and Shortcuts INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES The IOS CLI provides hot keys and shortcuts that make configuring, monitoring, and troubleshooting easier. Commands and keywords can be shortened to the minimum number of characters that identify a unique selection. For example, the configure command can be shortened to conf because configure is the only command that begins with conf. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES The Command Structure Hot Keys and Shortcuts (Cont.) ▪ The table below is a brief list of keystrokes to enhance command line editing. Keystroke Description Tab Completes a partial command name entry. Backspace Erases the character to the left of the cursor. Left Arrow or Ctrl+B Moves the cursor one character to the left. Right Arrow or Ctrl+F Moves the cursor one character to the right. Recalls the commands in the history buffer, beginning with Up Arrow or Ctrl+P the most recent commands. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES The Command Structure Hot Keys and Shortcuts (Cont.) When a command output produces The table below lists commands that more text than can be displayed in a can be used to exit out of an terminal window, the IOS will display operation. a “--More--” prompt. The table below describes the keystrokes that can be used when this prompt is displayed. Keystroke Description Keystroke Description When in any configuration mode, ends the Enter Key Displays the next line. Ctrl-C configuration mode and returns to privileged EXEC mode. When in any configuration mode, ends the Space Bar Displays the next screen. Ctrl-Z configuration mode and returns to privileged EXEC mode. Ends the display string, returning to All-purpose break sequence used to abort DNS Any other key Ctrl-Shift-6 privileged EXEC mode. lookups, traceroutes, pings, etc. Note: To see more hot keys and shortcuts refer to 2.3.5. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES The Command Structure Video – Hot Keys and Shortcuts This video will cover the following: Tab key (tab completion) Command shortening Up and down arrow key CTRL + C CTRL + Z CTRL + Shift + 6 CTRL + R 2.4 Basic Device Configuration © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 23 INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Basic Device Configuration Device Names The first configuration command on any device should be to give it a unique hostname. By default, all devices are assigned a factory default name. For example, a Cisco IOS switch is "Switch.” Guideline for naming devices: Start with a letter Contain no spaces End with a letter or digit Note: To return the switch to the default Use only letters, digits, and dashes prompt, use the no hostname global Be less than 64 characters in length config command. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Basic Device Configuration Password Guidelines The use of weak or easily guessed passwords are a security concern. All networking devices should limit administrative access by securing privileged EXEC, user EXEC, and remote Telnet access with passwords. In addition, all passwords should be encrypted and legal notifications provided. Password Guidelines: Use passwords that are more than eight characters in length. Use a combination of upper and lowercase letters, numbers, special characters, and/or numeric sequences. Note: Most of the labs in this course use simple Avoid using the same password for all devices. passwords such as cisco or class. These passwords are considered weak and easily guessable and should Do not use common words because they are be avoided in production environments. easily guessed. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Basic Device Configuration Configure Passwords Securing user EXEC mode access: First enter line console configuration mode using the line console 0 command in global configuration mode. Next, specify the user EXEC mode password using the password password command. Finally, enable user EXEC access using the login command. Securing privileged EXEC mode access: First enter global configuration mode. Next, use the enable secret password command. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Basic Device Configuration Configure Passwords (Cont.) Securing VTY line access: First enter line VTY configuration mode using the line vty 0 15 command in global configuration mode. Next, specify the VTY password using the password password com mand. Finally, enable VTY access using the login command. ▪ Note: VTY lines enable remote access using Telnet or SSH to the device. Many Cisco switches support up to 16 VTY lines that are numbered 0 to 15. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Basic Device Configuration Encrypt Passwords ▪ The startup-config and running-config files ▪ Use the show running-config display most passwords in plaintext. command to verify that the passwords ▪ To encrypt all plaintext passwords, use on the device are now encrypted. the service password-encryption global config command. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Basic Device Configuration Banner Messages ▪ A banner message is important to warn unauthorized personnel from attempting to access the device. ▪ To create a banner message of the day on a network device, use The banner will be displayed on attempts to the banner motd # the message of access the device. the day # global config command. Note: The “#” in the command syntax is called the delimiting character. It is entered before and after the message. 2.5 Save Configurations © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 30 INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Save Configurations Configuration Files ▪ There are two system files that store the device configuration: startup-config - This is the saved configuration file that is stored in NVRAM. It contains all the commands that will be used by the device upon startup or reboot. Flash does not lose its contents when the device is powered off. running-config - This is stored in Random Access Memory (RAM). It reflects the current configuration. Modifying a running configuration affects the operation of a Cisco device immediately. RAM is volatile memory. It loses all of its content when the device is powered off or restarted. To save changes made to the running configuration to the startup configuration file, use the copy running-config startup-config privileged EXEC mode command. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Save Configurations Alter the Running Configurations If changes made to the running config do not have the desired effect and the running-config has not yet been saved, you can restore the device to its previous configuration. To do this you can: Remove the changed commands individually. Reload the device using the reload command in privilege EXEC mode. Note: This will cause the device to briefly go offline, leading to network downtime. If the undesired changes were saved to the startup-config, it may be necessary to clear all the configurations using the erase startup- config command in privilege EXEC mode. After erasing the startup-config, reload the device to clear the running-config file from RAM. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Save Configurations Capture Configuration to a Text File Configuration files can also be saved and archived to a text document. Step 1. Open terminal emulation software, such as PuTTY or Tera Term, that is already connected to a switch. Step 2. Enable logging in to the terminal software and assign a name and file location to save the log file. The figure displays that All session output will be captured to the file specified (i.e., MySwitchLogs). INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Save Configurations Capture Configuration to a Text File (Cont.) Step 3. Execute the show running- config or show startup-config command at the privileged EXEC prompt. Text displayed in the terminal window will be placed into the chosen file. Step 4. Disable logging in the terminal software. The figure shows how to disable logging by choosing the None session logging option Note: The text file created can be used as a record of how the device is currently implemented. The file could require editing before being used to restore a saved configuration to a device. 2.6 Ports and Addresses © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 35 INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Ports and Addresses IP Addresses The use of IP addresses is the primary means of enabling devices to locate one another and 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. An IPv4 subnet mask is a 32-bit value that differentiates the network portion of the address from the host portion. Coupled with the IPv4 address, the subnet mask determines to which subnet the device is a member. The default gateway address is the IP address of the router that the host will use to access remote networks, including the internet. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Ports and Addresses IP Addresses (Cont.) IPv6 addresses are 128 bits in length and written as a string of hexadecimal values. Every four bits is represented by a single hexadecimal digit; for a total of 32 hexadecimal values. Groups of four hexadecimal digits are separated by a colon “:”. IPv6 addresses are not case-sensitive and can be written in either lowercase or uppercase. Note: IP in this course refers to both the IPv4 and IPv6 protocols. IPv6 is the most recent version of IP and is replacing the more common IPv4. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Ports and Addresses Interfaces and Ports Network communications depend on end user device interfaces, networking device interfaces, and the cables that connect them. Types of network media include twisted-pair copper cables, fiber-optic cables, coaxial cables, or wireless. Different types of network media have different features and benefits. Some of the differences between various types of media include: Distance the media can successfully carry a signal Environment in which the media is to be installed Amount of data and the speed at which it must be transmitted Cost of the media and 2.7 Configure IP Addressing © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 39 INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Configure IP Addressing Manual IP Address Configuration for End Devices End devices on the network need an IP address in order to communicate with other devices on the network. IPv4 address information can be entered into end devices manually, or automatically using Dynamic Host Configuration Protocol (DHCP). To manually configure an IPv4 address on a Windows PC, 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. Next, click Properties to open the Internet Protocol Version 4 (TCP/IPv4) Properties window. Then configure the IPv4 address and subnet mask information, and default gateway. Note: IPv6 addressing and configuration options are similar to IPv4. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Configure IP Addressing Automatic IP Address Configuration for End Devices DHCP enables automatic IPv4 address configuration for every end device that is DHCP-enabled. End devices are typically by default using DHCP for automatic IPv4 address configuration. To configure DHCP on a Windows PC, 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. Next, click Properties to open the Internet Protocol Version 4 Note: IPv6 uses DHCPv6 and SLAAC (Stateless Address (TCP/IPv4) Properties window, Autoconfiguration) for dynamic address allocation. then select Obtain an IP address automatically and Obtain DNS server address automatically. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Configure IP Addressing Switch Virtual Interface Configuration To access the switch remotely, an IP address and a subnet mask must be configured on the SVI. To configure an SVI on a switch: Enter the interface vlan 1 command in global configuration mode. Next assign an IPv4 address using the ip address ip-address subnet- mask command. Finally, enable the virtual interface using the no shutdown command. 2.8 Verify Connectivity © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 43 INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Verify Connectivity Video – Test the Interface Assignment This video will cover the following: ▪ Connect a console cable from the PC to the switch ▪ Use the terminal emulation program and accept the defaults to bring you to the command line ▪ Use enable to enter privileged EXEC mode ▪ Use the global configuration mode and the interface configuration mode to enter the no shutdown command INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Verify Connectivity Video – Test End-to-End Connectivity This video will cover the use of the ping command to test connectivity on both switches and both PCs. 2.9 Module Practice and Quiz © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 46 INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Module Practice and Quiz What did I learn in this module? All end devices and network devices require an operating system (OS). Cisco IOS software separates management access into the following two command modes: User EXEC Mode and Privileged EXEC Mode. Global configuration mode is accessed before other specific configuration modes. From global config mode, the user can enter different subconfiguration modes. Each IOS command has a specific format or syntax and can only be executed in the appropriate mode. Basic device configurations- hostname, password, encrypt passwords and banner. There are two system files that store the device configuration: startup- config and running-config. IP addresses enable devices to locate one another and establish end- to-end communication on the internet. Each end device on a network must be configured with an IP address. INSTITUTE COLLEGE OFOF INFORMATION INFORMATION ANDAND COMPUTING COMPUTING SCIENCES SCIENCES Let’s play