command set provides a horizontal scrolling
feature for commands that extend beyond a single line on the
screen. When the cursor reaches the right margin, the command
line shifts ten spaces to the left. The first ten characters of
the line cannot be seen, but a user can scroll back and check
the syntax at the beginning of the command. To scroll back,
press Ctrl-B or the left arrow key repeatedly until the
beginning of the command entry is reached. Ctrl-A will
return a user directly to the beginning of the line. In the
example shown in Figure , the command entry extends beyond one
line. When the cursor first reaches the end of the line, the
line is shifted ten spaces to the left and redisplayed. The
dollar sign ($) indicates that the line has been
scrolled to the left. Each time the cursor reaches the end of
the line, the line is again shifted ten spaces to the left.
Screen output varies, depending on Cisco IOS software level and
router configuration. Ctrl-Z is a command used to back
out of configuration mode. This will return the user to the
privileged EXEC mode prompt. Interactive Media
Activity Drag and Drop: Enhanced Editing Commands After
completing this activity, the student will be able to identify
the correct usage for enhanced editing commands. Web
Links editing Command
http://www.cisco.com/en/US/products/sw/
iosswrel/ps1835/products_command_reference_
chapter09186a00800ca73c.html#1017434
Content 2.2
Starting a Router 2.2.8 Router command
history The user interface provides a history or record of
commands that have been entered. This feature is particularly
useful for recalling long or complex commands or entries. With
the command history feature, the following tasks may be
completed: - Set the command history buffer size
- Recall commands
- Disable the command history
feature
The command history is enabled by default
and the system records ten command lines in its history buffer.
To change the number of command lines the system records during
a terminal session, use the terminal history size or the
history size command. The maximum number of commands is
256. To recall commands in the history buffer beginning with
the most recent command, press Ctrl-P or the up arrow
key repeatedly to recall successively older commands. To return
to more recent commands in the history buffer, after recalling
commands with Ctrl-P or the up arrow, press
Ctrl-N or the down arrow key repeatedly to recall
successively more recent commands. When typing commands, as a
shortcut, the unique characters may be entered for a command.
Press the Tab key, and the interface will finish the
entry. When the typed letters uniquely identify the command,
the Tab key simply acknowledges visually that the router
has understood the specific command that was intended. On most
computers additional select and copy functions are available. A
previous command string may be copied and then pasted or
inserted as the current command entry. Interactive Media
Activity Drag and Drop: Router Command History When the
student has completed this activity, the student will be able
to identify the correct usage for keystrokes relating to router
command history. Web Links Basic Command-Line Interface
Commands http://www.cisco.com/en/US/products/sw/
iosswrel/ps1835/products_command_reference_
hapter09186a00800ca73c.html#xtocid21
Content 2.2
Starting a Router 2.2.9 Troubleshooting
command line errors Command line errors occur primarily
from typing mistakes. If a command keyword is incorrectly typed
the user interface provides error isolation in the form of an
error indicator (^). The "^" symbol
appears at the point in the command string where an incorrect
command, keyword, or argument was entered. The error location
indicator and interactive help system allow the user to easily
find and correct syntax errors. Router#clock set 13:32:00 23
February 93 ^ % Invalid input detected at
"^" marker. The caret symbol (^) and
help response indicate an error at 93. To list the correct
syntax, enter the command up to the point where the error
occurred and then enter a question mark (?):
Router#clock set 13:32:00 23 February ?
<1993-2035> Year
Router#clock set 13:32:00 23
February Enter the year using the correct syntax and press
Return to execute the command. Router#clock set
13:32:00 23 February 1993 If a command line is entered
incorrectly, and the enter key is pressed, the up arrow can be
pressed to repeat the last command. Use the right and left
arrow keys to move the cursor to the location where the mistake
was made. Then type the correction that needs to be made. If
something needs to be deleted, use the <backspace> key.
Lab Activity Lab Exercise: Command Line Fundamentals In
this lab, the student will log into a router in both user and
privileged modes and use several basic router commands to
determine how the router is configured. Web Links
editing Command http://www.cisco.com/en/US/products/sw/
iosswrel/ps1835/products_command_reference_
chapter09186a00800ca73c.html#1017434
Content 2.2
Starting a Router 2.2.10 The show version
command The show version command displays
information about the Cisco IOS software version that is
currently running on the router. This includes the
configuration register and the boot field settings. Figure
shows the following information from the show version
command: - IOS version and descriptive information
- Bootstrap ROM version
- Boot ROM version
- Router up time
- Last restart method
- System image file and location
- Router platform
- Configuration register setting
Use the
show version command to identify router IOS image and
boot source. Web Links show version Command
http://www.cisco.com/en/US/products/sw/
iosswrel/ps1835/products_command_reference_
chapter09186a00800ca743.html#1018369
Content
Summary An understanding of the following key points should
have been achieved: - The purpose of the IOS
- The basic operation of the IOS
- Identification of
various IOS features
- Identification of the methods to
establish a CLI session with the router
- The
differences between the user EXEC and privileged EXEC modes
- Establishing a HyperTerminal session
- Logging into the router
- Using the help feature in
the command line interface
- Using enhanced editing
commands
- Using command history
- Troubleshooting command line errors
- Using the
show version command