Skip to main content

Keyboard help in the router CLI

Keyboard help in the router CLI
2.2.6 This page will introduce some router help functions.


A question mark, ?, can be entered at the user EXEC or privileged EXEC mode prompt to display a list of available commands. Notice the --More-- at the bottom of the display in Figure . The --More-- prompt indicates that there are multiple screens of output. When a --More-- prompt appears, press the Spacebar to view the next available screen. To display just the next line, press the Return or Enter key. Press any other key to return to the prompt.

To access privileged EXEC mode, type enable or the abbreviation en or ena. This might cause the router to prompt the user for a password if one has been set. Figure lists the commands that are available in privileged EXEC mode.

Screen output varies, depending on Cisco IOS software level and router configuration.

The help function, or question mark, ?, can be used to display the commands that are used to perform certain tasks. The following exercise illustrates one of the many uses of the help function.

If a user wants to set the router clock and does not know the command, the help function can be used as follows:

1. Use ? to find the command for setting the clock. The help output shows that the clock command is required.

2. Check the syntax for changing the time.

3. Enter the current time by using hours, minutes, and seconds, as shown in Figure . The system indicates that additional information needs to be provided to complete the command.

4. Press Ctrl-P or the Up Arrow to repeat the previous command entry. Then add a space and a question mark (?) to reveal the additional arguments. Now the command entry can be completed.

5. The caret symbol (^) and help response indicate an error. The placement of the caret symbol shows where the possible problem is located. To input the correct syntax, re-enter the command up to the point where the caret symbol is located and then enter a question mark (?).

6. Enter the year, using the correct syntax, and press Return or Enter to execute the command.

As demonstrated in the IOS Auto-Completion e-Lab, typing an abbreviated command, such as sh, followed by the Tab key completes a partial command name.

The next page will introduce some enhanced editing commands that are available in the Cisco IOS.

Comments

Popular posts from this blog

OSI layers / Peer-to-peer communications / TCP/IP model

OSI layers 2.3.4 This page discusses the seven layers of the OSI model. The OSI reference model is a framework that is used to understand how information travels throughout a network. The OSI reference model explains how packets travel through the various layers to another device on a network, even if the sender and destination have different types of network media. In the OSI reference model, there are seven numbered layers, each of which illustrates a particular network function. - Dividing the network into seven layers provides the following advantages: • It breaks network communication into smaller, more manageable parts. • It standardizes network components to allow multiple vendor development and support. • It allows different types of network hardware and software to communicate with each other. • It prevents changes in one layer from affecting other layers. • It divides network communication into smaller parts to make learning it easier to understand. In the foll...

PC Basic...

• Backplane – A backplane is an electronic circuit board containing circuitry and sockets into which additional electronic devices on other circuit boards or cards can be plugged; in a computer, generally synonymous with or part of the motherboard. • Network interface card (NIC) – An expansion board inserted into a computer so that the computer can be connected to a network. • Video card – A board that plugs into a PC to give it display capabilities. • Audio card – An expansion board that enables a computer to manipulate and output sounds. • Parallel port – An interface capable of transferring more than one bit simultaneously that is used to connect external devices such as printers. • Serial port – An interface that can be used for serial communication in which only one bit is transmitted at a time. • Mouse port – A port used to connect a mouse to a PC. • USB port – A Universal Serial Bus connector. A USB port connects devices such as a mouse or printer to the computer ...

Windowing

Windowing 11.1.5 This page will explain how windows are used to transmit data. Data packets must be delivered to the recipient in the same order in which they were transmitted to have a reliable, connection-oriented data transfer. The protocol fails if any data packets are lost, damaged, duplicated, or received in a different order. An easy solution is to have a recipient acknowledge the receipt of each packet before the next packet is sent. If a sender had to wait for an ACK after each packet was sent, throughput would be low. Therefore, most connection-oriented, reliable protocols allow multiple packets to be sent before an ACK is received. The time interval after the sender transmits a data packet and before the sender processes any ACKs is used to transmit more data. The number of data packets the sender can transmit before it receives an ACK is known as the window size, or window. TCP uses expectational ACKs. This means that the ACK number refers to the next packet that is...