Chapter 2: Configuring a Network Operating System PDF

Chapter 2: Configuring a Network Operating System Introduction to Networks v7.0 (ITN) Module 2 Chapter 2 (reference: CCNA ver 7 ITN module 2) Topics ITN ref: Cisco IOS and IOS Access 2.1 IOS Navigat...

Chapter 2: Configuring a Network Operating System Introduction to Networks v7.0 (ITN) Module 2 Chapter 2 (reference: CCNA ver 7 ITN module 2) Topics ITN ref: Cisco IOS and IOS Access 2.1 IOS Navigation 2.2 The Command Structure 2.3 Basic IOS commands 2.4, 2.5 Configure IP Addressing 2.7 Verify Connectivity 2.8 © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 2 Cisco IOS and IOS Access © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 3 Cisco IOS Access Operating Systems All computing devices, eg computers, network devices and home wireless routers are dependent on operating systems (OS) or firmware. OS consists of: 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. Cisco IOS (Internetwork Operating System) is the OS running on Cisco networking devices. © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 4 Cisco IOS Access Accessing a Cisco IOS Device  Cisco router or switch does not have keyboard and screen.  Two category of methods to access, “out-of-band” and “in-band”.  Out-of-band Not using the network connection to get in. Use separate connection. Two main methods: Console Port - Need console cable to connect to console port. Auxilary Port - Need modem and telephone line connection. Device should be located in a secure room so console port cannot be easily accessed  In-band Uses network connection to get in Requires active networking services and one active interface that is configured Two main methods via virtual terminals (or VTY): telnet – Not so secure as communication is not encrypted. SSH – more secure as communication is encrypted. © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 5 Accessing a Cisco IOS Device Terminal Emulation Programs Software available for connecting to a networking device: PuTTY Tera Term SecureCRT HyperTerminal OS X Terminal © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 6 IOS Navigatoin © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 7 Navigating the IOS Cisco IOS Modes of Operation 1 - User Exec Mode 2 - Privileged Exec Mode User EXEC enable Privileged EXEC Router> disable Router# ping, show (limited) All User EXEC cmds enable, etc reload, configure, etc configure terminal end or z rl- exit Ct specific Other config exit Global config Router(config-x)# Router(config)# Commands specific to the hostname, ip route configuration interface gi0/0 enable secret etc router ospf 1 line console 0 4 - Other configuration mode etc 3 - Global configuration Mode © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 8 Navigating the IOS Navigating Between IOS Modes Video available in ITN 2.2.3 and 2.2.5 Going into other config mode Configure in global config mode No need to back out to global config mode if moving from one other config mode to another other config mode © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 9 The Command Structure © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 10 The Command Structure IOS Command Structure © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 11 The Command Structure Video available in Context-Sensitive Help – how to use ? ITN 2.3.4 and 2.3.6 No space between letter and ? IOS displays a list of commands or keywords that start with the characters cl A space between word and ? IOS displays what command arguments or variables can be next and provides an explanation for each. © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 12 The Command Structure IOS Error messages Incomplete command Wrong / invalid input Required keywords or arguments are IOS returns a ‘^’ character to indicate where not keyed in. Commands not complete the wrong or invalid command is entered Ambiguous command Not enough characters were entered for IOS to know exactly know what command is required © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 13 The Command Structure Hot Keys and Shortcuts  Tab – Completes the remainder of a partially typed command or keyword.  Ctrl-R – Redisplays a line.  Ctrl-A – Moves to the beginning of the line.  Ctrl-Z – Exits the configuration mode and returns to user EXEC.  Down Arrow – Allows the user to scroll forward through former commands.  Up Arrow – Allows the user to scroll backward through former commands.  Ctrl-shift-6 – Allows the user to interrupt an IOS process such as ping or traceroute.  Ctrl-C – Exits the current configuration or aborts the current command. © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 14 Basic IOS Commands © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 15 Basic IOS commands Basic IOS commands  show version show properties of the router or switch such as IOS version, amount of memory, device model etc.  hostname to configure a device name for the router or switch  service password-encryption converts all plain text passwords in the device to encrypted format. Any encrypted plain text passwords will stay encrypted even after “no service password- encryption” command is applied. no shutdown Administratively enables the interface. © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 16 Basic IOS commands Basic IOS commands - continued  banner motd # banner message # to configure a banner message on the device. Important part of legal process in the event someone is prosecuted for breaking into a device. Often used for legal notification because it is displayed to all connected terminals  show running-config or sh run to display running configuration file, ie what you have configured  copy run start to copy running configuration file to startup configuration file. Running configuration file is stored in RAM Startup configuration file is stored in NVRAM  erase startup-config to delete the startup configuration file. © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 17 Basic IOS commands Securing Device Access using passwords Use passwords to control access to IOS devices. Configure password to access privileged EXEC mode using enable secret command Configure password to secure access via console Configure password to secure access via VTY using telnet or SSH © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 18 Configure IP Addressing © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 19 Configure IP addresing Preparing for Basic Switch Management To remotely manage a Cisco switch, it must be configured with an IP address, subnet mask and default gateway if accessing from a remote network. These IP information is to allow remote access and management of the switch. A layer 2 switch will not route layer 3 packets © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 20 Configure IP Addressing IP Address Configuration for End Devices (Windows) Manual / Static DHCP / Dynamic © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 21 Verify Connectivity © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 22 Verifying Connectivity Testing End-to-End Connectivity Use ping command © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 23 End of Chapter © 2019 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 24