Router Startup and Setup& Router Configuration 1

Semester 2Chapter 5/6

By: William Widulski

Table of Contents

Boot Sequence and Setup Mode

System Configuration Dialog

Router Configuration Files

Router Configuration Modes

Configuration Methods

Challenge Labs

Router Boot Sequence and Setup Mode

Router Startup Routine

Router Startup Sequence

Related CommandsTable of Contents

Router Startup Routine When a Cisco router powers up, it

performs a power-on self test (POST). Executes diagnostics from ROM on all hardware Verifies the basic operation of the CPU,

memory, and network interface ports Proceeds with software initialization

A router initializes by loading the bootstrap, the IOS, and a configuration file. If the router cannot find a configuration file,

then it enters setup mode NVRAM stores a backup copy of the new

configuration from setup mode

Router Startup Routine The goal of the startup routines for Cisco

IOS software is to start the router operations. The router must deliver reliable performance in its job of connecting the user networks it was configured to serve. To do this, the startup routines must: Make sure that the router comes up with all its

hardware tested. Find and load the Cisco IOS software that the

router uses for its operating system. Find and apply the configuration statements

about the router, including protocol functions and interface addresses.

Router Startup Sequence After the power-on self test on the router,

the following events occur as the router initializes: Step 1 - The generic bootstrap loader, in ROM, executes

on the CPU card. A bootstrap is a simple, preset operation to load instructions that in turn cause other instructions to be loaded into memory, or cause entry into other configuration modes.

Step 2 - The operating system (Cisco IOS) can be found in one of several places. The location is disclosed in the boot field of the configuration register. If the boot field indicates a Flash, or network load, boot system commands in the configuration file indicate the exact location of the image.

Step 3 - The operating system image is loaded. Then, when it is loaded and operational, the operating system locates the hardware and software components and lists the results on the console terminal.

Router Startup Sequence Step 4 -- The configuration file saved in

NVRAM is loaded into main memory and executed one line at a time. These configuration commands start routing processes, supply addresses for interfaces, set media characteristics, and so on.

Step 5 -- If no valid configuration file exists in NVRAM, the operating system executes a question-driven initial configuration routine referred to as the system configuration dialog, also called the setup dialog.

Setup is not intended for entering complex protocol features in the router. It is used to bring up a minimal configuration.

Know the sequence!

Router Startup Sequence

Related Commands show startup-config (show config on

Cisco IOS 10.3 or earlier) – display the backup configuration file.

show running-config (write term on Cisco IOS 10.3 or earlier) – display the active configuration file.

erase startup-config (write erase on Cisco IOS 10.3 or earlier) – deletes the backup configuration file in NVRAM.

reload (reboot) command reloads the router, causing it to run through the entire startup process.

setup is used to enter setup mode from the privileged EXEC prompt

System Configuration Dialog

The setup Command Setting up global and

interface parameters Setting up script

review and use Setup Lab Challenge

Table of Contents

The setup Command The main purpose of the setup mode is to

bring up, quickly, a minimal configuration for any router that cannot find its configuration from another source.

Default answers appear in square brackets [ ] following the question. Press the Return key to use these defaults.

During the setup process, you can press Control+C at any time to terminate the process and start over.

Once setup is terminated, all interfaces will be administratively shutdown.

The setup Command When you completed, the screen will

display the configuration that you have just created.

You will then be asked whether you want to use this configuration. If you enter "yes", the configuration will be

executed and saved to NVRAM. If you answer "no", the configuration will not be

saved and the process will begin again. If a --More-- prompt appears, press the

space bar to continue..

Setting Global Parameters After viewing the current interface

summary, a prompt will appear on your monitor, indicating that you are to enter the global parameters for your router.

Configuring global parameters appears on your monitor. It indicates that you are to enter the global parameters that you set for your router.

The first global parameter allows you to set the router host name. This host name will be part of the Cisco IOS

prompts for all configuration modes. At initial configuration, the default router name

is [Router].

Setting Global Parameters The next global parameters allows you to set the

various passwords used on the router. You must enter an enable password. When you enter a string of password characters for the

prompt, "Enter enable secret"; the characters are processed by Cisco proprietary encryption.

This enhances the security of the password string. Whenever anyone lists the contents of the router

configuration file, this enable password appears as a meaningless string of characters.

Setup recommends, but does not require, that the "enable password" be different from the "enable secret word".

Setting Global Parameters The "enable secret word" is a one-

way cryptographic secret word that is used instead of the "enable password" when it exists. The "enable password" is used when no "enable secret word" exists. It is also used when using older versions of the IOS.

All passwords are case sensitive and can be alphanumeric.

Setting Global Parameters When you are prompted for

parameters for each installed interface, use the configuration values that you have selected for your router.

Whenever you answer yes to a prompt, additional questions may appear regarding the protocol.

Interface Parameters When you are prompted for

parameters for each installed interface, you need to use the configuration values you have determined for your interface to enter the interface parameters at the prompts

In order to fully understand setup mode complete the Lab Lab 5.2.3 Router setup command

Script Review and Use When you complete the configuration process for

all installed interfaces on your router, the setup command program will display the configurations that you have created.

The setup process will then ask if you want to use this configuration. If you answer yes, the configuration will be executed

and saved to NVRAM. If you answer no, the configuration will not be saved,

and the process will begin again. There is no default for this prompt; you must answer

either yes or no. After you have answered yes to the last question, your

system will be ready to use. If you want to modify the configuration you have just

established, you must do the configuration manually.

Script Review and Use The script tells you to use the

configuration mode to change any commands after setup has been used.

The script file generated by setup is additive; you can turn features on with setup, but you cannot turn them off.

Also, setup does not support many of the advanced features of the router, or features that require a more complex configuration.

Challenge Lab Your Skills Assessment will be based

on this Lab, make sure you have completed it… Lab 5.3.1 Router setup challenge

Summary The router initializes by loading a

bootstrap, the operating system, and a configuration file.

If the router cannot find a configuration file, the router enters setup mode.

The router stores a backup copy of the new configuration from setup mode in NVRAM.

Router Configuration Files

Table of Contents

Configuration File Info Configuration files can come from the console,

NVRAM, or a TFTP server. A router uses information from the configuration

file when it starts up: Cisco IOS software version Router identification Boot file locations Protocol information Interface configurations

The configuration file contains commands to customize router operation.

If there is no configuration file available, the system configuration dialog setup guides you through the process of creating one

Release 11.x Config-Files Router configuration can be done in

several ways. You can use the privileged EXEC configure command to

configure from a virtual (remote) terminal, a modem connection, or a console terminal.

You can enter changes to an existing configuration at any time.

You can use the privileged EXEC configure command to load a configuration from a network TFTP server, which allows you to maintain and store configuration information at a central site.

Release 11.x Config-Files Some configuration commands include:

configure terminal – configures manually from the console terminal

configure memory – loads configuration information from NVRAM

copy tftp running-config – loads configuration information from a network TFTP server into RAM

show running-config – displays the current configuration in RAM

copy running-config startup-config – stores the current configuration from RAM into NVRAM

copy running-config tftp – stores the current configuration from RAM on a network TFTP server

show startup-config – displays the saved configuration, which is the contents of NVRAM

erase startup-config – erases the contents of NVRAM

Lab To fully understand Router configuration,

do the lab. Lab 6.1.2 Router config HyperTerminal

Pre-Release 11.0 config-files The commands used with Cisco IOS,

Release 10.3 and earlier, have been replaced with new commands.

The old commands that have been replaced continue to perform their normal functions in the current release, but are no longer documented

Support for these commands will cease in a future release

Early Commands Configuration commands for Release 10.3 and

earlier: config term – configures manually from the console

terminal config mem – loads configuration information from

NVRAM config net – loads configuration information from a

network TFTP server into RAM write term – displays the current configuration in RAM write mem– stores the current configuration from RAM

into NVRAM write net – stores the current configuration from RAM

on a network TFTP server show config – displays the saved configuration, which is

the contents of NVRAM write erase – erases the contents of NVRAM

Copying to a TFTP Server To store (backup) the current copy of the

configuration file in RAM on a TFTP server use the copy running-config tftp command and complete the following tasks: Step 1 – Enter the copy running-config tftp

command. Step 2 – Enter the IP address of the host that

you want to use to store the configuration file. Step 3 – Enter the name you want to assign to

the configuration file. Step 4 – Confirm your choices by answering

yes each time.

Copying from a TFTP Server To configure a router by loading the

configuration file stored on one of your network TFTP servers, complete the following tasks: Enter the command copy tftp running-config At the prompt, select a host or network

configuration file. • The network configuration file contains commands

that apply to all routers and terminal servers on the network.

• The host configuration file contains commands that apply to one router in particular.

At the next prompt, enter the IP address of the the TFTP server from which you are retrieving the configuration file.

Copying from a TFTP Server Finally, enter the name of the

configuration file or accept the default name. The filename convention is UNIX-based. The default filename is hostname -confg for

the host file and network -confg for the network configuration file.

In the DOS environment, the server filenames are limited to eight characters plus a three-character extension (e.g., router.cfg).

Confirm the configuration filename and the server address that the system supplies.

Lab Note: You must configure the default

gateway IP address that the TFTP server is attached to on the Router or the lab will not work Lab 6.1.4 Router Configuration TFTP

NVRAM Commands These commands manage the contents of

NVRAM with Release 11.x: configure memory – Loads configuration

information from NVRAM. erase startup-config – Erases the contents of

NVRAM. copy running-config startup-config – Stores

the current configuration from RAM (the running configuration) into NVRAM (as the startup or backup configuration).

show startup-config – Displays the saved configuration, which is the contents of NVRAM.

NVRAM Commands These commands manage the contents of

NVRAM with Release 10.3 and earlier: configure memory – Loads configuration

information from NVRAM. write erase – Erases the contents of NVRAM. write memory – Stores the current

configuration from RAM (the running configuration) into NVRAM (as the startup or backup configuration).

show configuration – Displays the saved configuration, which is the contents of NVRAM.

Router Configuration Modes

Table of Contents

Using Configuration Modes The EXEC mode interprets the commands

you type and carries out the corresponding operations.

You must log into the router before you can enter an EXEC command.

There are two EXEC modes (user mode and privileged mode).

The EXEC commands available in user mode are a subset of the EXEC commands available in privileged mode.

From privileged mode, you can also access global configuration mode and specific configuration modes

Using Configuration Modes Some specific configuration modes are:

Interface Subinterface Controller Map-list Map-class Line Router IPX-router Route-map

If you type exit, the router will back out one level, eventually allowing you to log out. In general, typing exit from one of the specific configuration modes will return you to global configuration mode.

Pressing Ctrl-Z leaves configuration mode completely and returns the router to privileged EXEC mode.

Overview of Router Modes

Lab Complete the following lab :

Lab 6.2.1 Basic router configuration You can also use the “Seven steps to

Router Configuration Heaven” handout: http://cisco.netacad.net/ccnaDownloads/

2/wwidulsk_Seven_Steps_to_Router_Configuration_Heaven.doc

Global Configuration Modes Global configuration commands apply to features that affect

the system as a whole. Use the privileged EXEC command configure to enter

global configuration mode. When you enter this command, the EXEC prompts you for the source of the configuration commands.

Specify terminal, NVRAM, or a file stored on a network server as the source. The default is to type in commands from the terminal console. Pressing the return key begins this configuration method.

Commands to enable a particular routing or interface function begin with global configuration commands: To configure a routing protocol (indicated by the prompt

config-router) you first enter a global router protocol command type.

To configure an interface (indicated by the prompt config-if) you first enter the global interface type and number command. After entering commands in any of these modes, you finish with the command exit.

Configuring Routing Protocol After a routing protocol is enabled by

a global command, the router configuration mode prompt Router (config-router)# is displayed.

Type a question mark (?) to list the routing protocol configuration sub-commands

Interface Config Commands Because all router interfaces are

automatically in the administratively down mode, many features are enabled on a per-interface basis.

Interface configuration commands modify the operation of an Ethernet, a Token Ring, or a serial port.

In addition, interface subcommands always follow an interface command because the interface command defines the interface type

Configuring a Specific Int On serial links, one side must provide a clocking

signal, a DCE; the other side is a DTE. By default, Cisco routers are DTE devices, but in

some cases they can be used as DCE devices. If you are using an interface to provide clocking,

you must specify a rate with the clockrate command.

The bandwidth command overrides the default bandwidth that is displayed in the show interfaces command and is used by some routing protocols such as IGRP. On the Cisco 4000 series routers, there are two

connections on the outside of the box for Ethernet interfaces-an attachment unit interface (AUI) connector and a 10BASE-T connector. The default is AUI, so you must specify media-type 10BASE-T if you want to use the other connection

Lab You will get a better handle on all this

after completing the Lab Lab 6.2.5 Router interface config

Configuration Methods

Table of Contents

Release 11.x Config Method The Figure shows a

way you can: Enter configuration

statements Examine the changes

you have made If necessary, modify or

remove configuration statements

Save the changes to a backup in NVRAM that the router will use when it starts up

Pre-11.0 Release Config

Password Config Methods You can secure your system by using passwords to restrict

access. Passwords can be established both on individual lines and in

the privileged EXEC mode. line console 0 – establishes a password on the console

terminal line vty 0 4 – establishes password protection on incoming

Telnet sessions enable password – restricts access to privileged EXEC mode enable secret password (from the system configuration dialog

to set up global parameters – uses a Cisco proprietary encryption process to alter the password character string

You can further protect passwords from being displayed by using the service password-encryption command. This encryption algorithm does not match the Data Encryption Standard (DES).

Router Identification Config The configuration of network devices determines the

network's behavior. To manage device configurations, you need to list and compare configuration files on running devices, store configuration files on network servers for shared access, and perform software installations and upgrades.

One of your first basic tasks is to name your router. The name of the router is considered to be the host name and is the name displayed by the system prompt. If you do not configure a name, the system default router name will be Router. You can name the router in global configuration mode.

You can configure a message-of-the-day banner to be displayed on all connected terminals. This banner will be displayed at login and is useful for conveying messages that affect all router users (e.g. impending system shutdowns). To configure this message, use the banner motd command in the global configuration mode.

Challenge Labs

Table of Contents

Configuration Labs To master router configuration, do the

labs. Lab 6.4.1 Router configuration challenge Lab 6.4.2 Cisco configmaker Lab 6.4.3 Router config. web browser

Active mental participation in answering lab questions is crucial to do well on the test.

You will also retain the knowledge longer if you think about what you are doing and why!