Unit 18 Cisco IOS command line

Cisco IOS command line interface (CLI)

text-based program that enables entering and executing Cisco IOS commands to configure, monitor, and maintain Cisco devices. can be used with either in-band or out-of-band management tasks.

CLI commands

sed to alter the configuration of the device and to display the current status of processes on the router. offers many time-saving features for creating both simple and complex configurations.

User EXEC mode

mode allows access to only a limited number of basic monitoring commands. It is often referred to as “view-only" mode. identified by the CLI prompt that ends with the > symbol.

Privileged EXEC mode

Mode allows access to all commands and features. The user can use any monitoring commands and execute configuration and management commands. identified by the prompt ending with the # symbol.

Syntax checker

given a set of instructions to enter a specific set of commands. cannot progress unless the exact and full command is entered as specified.

enable command

command to enter privileged EXEC mode

Syntax for a command

command followed by appropriate keywords and arguments, keyword, argument

Keyword

specific parameter defined in the operating system (in the figure, ip protocols).

Argument

not predefined; it is a value or variable defined by the user (in the figure, 192.168.10.5).

enter key

submits the command to the command interpreter

boldface

indicates commands and keywords that you enter literally as shown

italics

indicates arguments for which you supply values

square brackets

indicate an optional element (keyword or argument)

braces

indicate a required element (keyword or argument)

show commands

display relevant information about the configuration and operation of the device. used by network technicians to view configuration files, check the statues of device interfaces and processes, verifying the device operational status.

show running-config

Verify the current configuration and settings.

show interfaces

Verify the interface status and see if there are any error messages.

show ip interfaces

Verify the layer 3 information of an interface

show arp

verify the list of known hosts on the local Ethernet LANS

show ip route

verify the layer 3 routing information

show protocols

verify which protocols are operational

show version

verify the memory, interfaces, and licenses of the device