Entering Commands

4-5

4
Partial Keyword Lookup
If you terminate a partial keyword with a question mark, alternatives that match th e
initial letters are provided. (Remember not to leave a space between the comm and
and question mark.) For example “s?” shows all the keywords starting with “s.”
Negating the Effect of Commands
For many configuration commands you can enter the prefix keyword “ no” to cancel
the effect of a command or reset the configuration to the default value. For example,
the logging command will log system messages to a host server. To disable
logging, specify the no logging command. This guide describes the negation effect
for all applicable commands.
Using Command History
The CLI maintains a history of commands that have been entered. You can scroll
back through the history of commands by pressing the up arrow key. Any command
displayed in the history list can be executed again, or first modified and then
executed.
Using the show history command displays a longer list of recently executed
commands.
Understanding Command Modes
The command set is divided into Exec and Configuration classes. Exec comm ands
generally display information on system status or clear statistical counters.
Configuration commands, on the other hand, modify interfac e parameters or enable
certain switching functions. These classes are further divided into different mod es.
Available commands depend on the selected mode. You can always enter a
question mark “?” at the prompt to display a list of the commands available for the
current mode. The command classes and associated modes are disp layed in the
following table:
Console#show s?
snmp sntp spanning-tree ssh startup-config
system
Console#
Table4-1. Co mmand Modes
Class Mode
Exec Normal
Privileged
Configuration Global*Access Control List
Interface
Line
VLAN Database
* You must be in Privileged Exec mode to access the Global configuratio n mode.
You must be in Global Configuration mode to access any of the other c onfiguration modes.