Cisco (Cisco) switches? C3750-e? 2. Common commands

Introduction after you log in to the CISCO switch, we will need to use some common operations, such as querying, restarting, and so on, where some of the commonly used operations are grouped together.

Query Help

In different modes, we can enter the question mark directly (? You can query all the commands that you can use in the current mode.

When entering a command, if you do not remember the full name of the command, enter the first few characters with a question mark (? ) , you can get all the commands that begin with these few characters.

After you have finished the command, you can add a space after the command, and then add a question mark (?) after the preceding paragraph. ) , you can get what's behind this command.

Simplify input commands

Under normal circumstances, we need to enter multiple words to complete a command, for example:Configure Terminal.

In the absence of conflict, we can enter a simplified command, for example:conf t, can also achieve effect, reduce the difficulty of memory.

name the device

In a network, multiple devices are often present, and the name of the device is the token that distinguishes the different devices. The command device needs to use the command hostnamein global configuration mode.

set up a device banner

The slogan here is actually a message to the administrator, such as indicating what the device is for, who it belongs to, and so on. Because only one device name is incomprehensible. Setting the banner needs to be done in global mode, using the command banner.

For example, the banner login command sets the banner that is displayed when a user logs on to a device. For example, the banner MOTD Command, which sets the daily banner, is displayed to the person who signed in to the device before the sign-in banner.

Error message hint

If you get the wrong command, the device will prompt you for incorrect command input.

In addition to the command keyword, the administrator may also be in the command line to the host name of a device and the command keyword input, so the device found that a word itself can not match, it will be considered a device hostname, and then will be to the Domain name server (DNS) query, and the process of the query need to wait, not interrupted , if your network does not have a DNS server, it is recommended that the production equipment to the unknown command to initiate domain name query. In global configuration mode, enter the command no IP domain-lookup .

If you enter the command again, you will not query the DNS domain name server and prompt the command error directly.

Log Messages

When an administrator is operating on a device, it is often interrupted by a pop-up log message, which is very annoying.

To avoid this situation, you can enter the console line configuration mode in global configuration mode and use the command logging synchronous.

Save Configuration

All content that is modified by the administrator is saved in the Run profile (Running-config), which takes effect immediately, but is not present after the restart, and the boot profile (startup-config) records the configuration that was performed before the configuration was last saved, which is retained after the system restarts. and will load and take effect on reboot. So if you need to save the currently modified configuration and still use it after the next reboot, use the command copy running-config startup-configin privileged mode and press ENTER when you are prompted for confirmation.

Restore the original configuration

When you need to restore the original configuration, only need to delete the boot configuration file (startup-config), restart the switch, in privileged mode using the command erase Startup-config, prompted to confirm the press ENTER.

Restart

When you need to restart the switch, you can use command reloadin privileged mode to prompt for confirmation by pressing ENTER.

Cisco (Cisco) switches? C3750-e? 2. Common commands