Download cisco ios linux cli

The "end" for "if" statements is "fi" which is "if" backwards. This is done for historical reasons. There are a set of conditional tests available for tests, which are prefixed by either "[[" or " ". See conditional testing below. A "for" loop is a control construct that loops over a given set of values, and executes a set of statements with a variable set to each of the values in turn.

Here is a simple example. A 'while" statement is used the same test syntax as an 'if' statement, and executes the statements in the following block until the test returns FALSE. An example is. Users can exit a 'while' or 'for' loop early by using a 'break' statement. Here is an example. In addition to 'break', the 'continue' statement can be used to stop executing statements in the loop, and restart the loop. A 'while' statement that is interrupted by a 'continue' will simply stop executing statements in the body of the loop and start the 'while' statement over again.

A 'for' statement that is interrupted by a continue will also start over, except that it will assign the next element in the list of values before doing so. Note "Continue" and 'break' statements have no effect outside of a loop. The result of these are interpreted by those commands in a somewhat counter-intuitive way:. The return value of any command can be displayed using the Cisco IOS. Note In order to enter "? The two built-in test facilities are '[[' and ' '. The first is for evaluating logical tests, and the second is for evaluating numerical expression tests.

Additionally, there are some numerical tests that can be used here. These are intended to be used with variables that contain integers floating point numbers are not supported , and will give unexpected results if given strings instead of numbers.

The ' ' can be used in tests. It has a different set of possibilities that can be performed than the '[[ ]]' syntax. Here is the list of tests that are available. All of the following expressions expect numeric values. If the result is non-zero, it will evaluate to TRUE.

Parenthesis can be used to group expressions. However, parenthesis must be quoted or escaped in order to be used. Any text between backquote characters will be interpreted as a command, and inserted as if it was typed in at the console.

Here is an example:. The 'interface' command lists the set of interfaces that match the supplied pattern. When we put it in back quotes, the matching interfaces are inserted into the command line. The result is seen by the Cisco IOS.

The IOS CLI has a facility to 'pipe' text from a command into a set of programs that can filter or redirect the output. The commands are executed concurrently, and print whatever the final command in the 'pipeline' prints. The arguments passed to the IOS. A simple example would be a function to set a description for an interface by using the Cisco IOS.

Any of the facilities of Cisco IOS. The built-in Cisco IOS. These built-in functions supply various utilities that can be used along with Cisco IOS. The following is the set of Cisco IOS. To access the built-in Cisco IOS. Join us in congratulating October's Spotlight Award Winners! Turn on suggestions. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. Showing results for. Search instead for.

Did you mean:. All Community This category This board. Labels: Labels: Network Management. All forum topics Previous Topic Next Topic. Flavio Miranda. In response to Flavio Miranda.

In response to prashant Hi, yes, you can use sftp. Leo Laohoo. To get full access to the switch, we have to enter privileged mode, also called enabled mode. Here is how to do this:. This tells us we are now in enabled mode, granting us full access to the switch. Type erase startup-config and the switch will ask you to remove all configuration files.

Between the brackets, you see confirm. If you see anything between [] you only have to press enter. Type delete flash:vlan. You only have to press enter to confirm what Cisco IOS tells us between the brackets. If you get an error that there is no such file, do not worry. It means someone else already deleted the VLAN information and you can continue. The show command is probably the most used command for Cisco IOS.

We can use it to fetch any information from the switch. The show version command gives us a lot of information about the switch, including the model, IOS image, and more. What if we want to see what MAC addresses the switch has learned? There is another command for that:. The show mac address-table dynamic command tells us all MAC addresses that the switch has learned.

What if we want to see the entire configuration of the switch? The show running-config command gives us the entire active configuration of the switch. There are also debug commands. If you want to see changes, you have to use the same show command a couple of times.

Debug commands allow us to see things in real-time. You will see some examples of debug commands in other lessons. When you take a new switch out of the box, it will work right away with its default empty configuration. It will behave just like any other unmanaged switch, it will start learning MAC addresses and forwards Ethernet frames.

However, you probably want to make some changes to the configuration of your switch. Change its default hostname, perhaps add an IP address so you can manage it remotely, etc. To do this, we have to use configuration mode. In this mode, we can make changes to the configuration of the switch. With the configure terminal command, we enter configuration mode. Now we can make changes to the switch. When we want to make changes to interfaces or console settings, we have to dive into one of the configuration sub modes.

First, we use the line console 0 command to dive into the line configuration. You can recognize this because it shows config-line. I used the password command to specify a password cisco and the login command to tell the switch to ask for this password. Next time you access the console, it will ask for this password. First, I use the interface command and specify the interface that I want to make changes to.

You can see we are now in the interface sub-mode as it shows config-if to us. The first time, it jumps back to global configuration mode. The second time I do it, we jump back to enable mode and exit the configuration mode:. Everything we configure on our switch is applied to the running configuration. If we want to save our configuration, we have to save it as the startup configuration which is saved in NVRAM.

Next time we boot our switch, it will look for the startup configuration and use that. Use the copy command to copy the running configuration to the startup configuration. You have now seen the basics of Cisco IOS. We used some show commands and a few configuration commands. The CLI has some tricks up its sleeve to make your life easier. Not sure what the command was again or how to type it? The question mark is your friend. If you use it, it will tell you all possible commands:.