CCNA Guide to Cisco Networking Chapter 6: Router and IOS Basics

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

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

Benefits Of Routing Packet filtering Traffic control Connect LANs WAN connections Segmentation

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)

Cisco Router User Interface (continued)

Cisco Router User Interface (continued)

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

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

System Configuration Dialog (continued)

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 (>) User EXEC mode or user mode View basic settings and monitoring Question mark (?) Context-sensitive help

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 (>) Exec mode commands that can will affect router operations Setup Copy Erase

User Interface (continued)

Configuration Modes Global configuration mode Interface mode Router(config)# Interface mode Router(config–if)# Line configuration mode Router(config-line)# Router configuration mode Router(config-router)#

Configuration Modes (continued)

Configuration Modes (continued) “exit” command Crtl+Z Incorrect character symbol (^) Command shortcuts Example: show running-config or sh ru

Configuration Modes (continued)

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

Plethora Of Passwords (continued)

Plethora Of Passwords (continued)

Plethora Of Passwords (continued)

Plethora Of Passwords (continued)

Plethora Of Passwords (continued)

Plethora Of Passwords (continued)

Enhanced Editing

Command History Retrieve previously typed commands Stores up 10 previously typed commands by default Up arrow (Ctrl+P) Down arrow (Ctrl+N) Tab key to complete commands “terminal history” command 0 through 256

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

Configuring Router Identification (continued)

Configuring Router Identification (continued)

Configuring Router Identification (continued)

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

Configuring The Time And Date (continued)

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

Router Components ROM Flash memory NVRAM RAM/DRAM Interfaces

Router Components (continued) ROM Read-only memory (ROM) Bootstrap program ROM monitor firmware ROM monitor mode (>) or (rommon 1>)

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

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

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

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)

Summary Cisco routers use the Cisco IOS to provide an interface for network operators and administrators The first mode entered is user EXEC (router> 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

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

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

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