The 1^st mode that I would like to discuss about it is the Shell mode. This is represented by the percentage sign (%) by end of the prompt command. On this mode, the root (and only the root) will always go to it when he logs in to the Juniper router.

In this mode, the root user can do the file system commands and manage them. What does it mean by file system commands? This means that you can create a file, delete a file, see what is in the file, copy a file and so on.

The 2^nd mode that you should know on Juniper is the Operational mode. This is represented by the greater sign (>) by end of the prompt command. When you create a non-root user, and he logs in to the Juniper router, he will always go to the operational mode.

For the root user, to go from the shell modem to the operational mode he should use the command “CLI”.

In this mode, you can view the configuration. Meaning that any configuration on the router you can just check it from this mode using the “show” command most of the time. Also on this mode, you can do the troubleshooting using some application tools such as ping, traceroute. Also, you can connect remotely to other devices using SSH and Telnet. You can also reboot and shutdown the device from this mode.

So, in a summary, from the operational modem you can view the configuration on the router and using some utilities such as ping, traceroute to do the troubleshooting as well as some other utilities for some other tasks.

The last mode that we have on Juniper is the Configuration mode. This is represented by the hash sign (#) by end of the prompt command. To reach to this mode, you should be on the operational modem then write “edit” or “configure” then you can reach to this mode.

This mode is used to configure the router and to make changes on the router.

Those are the 3 different types of modes we have on the Juniper devices, let’s now apply a LAB to play with those 3 modes.

My PC is still connected via console to the router. I have just rebooted the router. Let’s connect to the root using the root username and password:

You can see that once I logged in to the root account, it took me to the shell modem which is represented by the (%) sign.

I have already mentioned that on the shell modem we can do everything related to the file management things. Let’s list what are the files that are available on the router:

Using the command “ls” I can list the files that are available.

Let’s see what the “.profile” file has as a content:

I used the command “cat” to see what is on this file. As you have already experienced, we are using command that normally we use on Linux environments, that’s because Juniper is based on FreeBSD as I have previously explained, meaning if you have some knowledge with Linux you may find Juniper very easy to be configured.

Now let’s do more things on this mode. I will copy the file “.profile” to another file called “.profile2” then I will delete it.

Let’s 1^st copy the file to “.profile2”:

I have successfully copied it and it is showing when I list the files again (the command to copy is “cp”).

Let me now delete “.profile2” using the remove command “rm”:

The file has been deleted successfully 😊

So now we understood more about the shell mode, let’s check the things that the operational mode can do.

To go to the operational mode from the shell mode, you need to write the command “CLI”:

Now we are on the operational mode.

Let’s make a question mark and see what commands I can use here:

As I have explained, you can use this mode to see things on the router using the “show” command, and to use utilities from troubleshooting such as ping and traceroute as well as to be able to connect remotely using Telnet and SSH.

Let’s for example see what the interfaces on the router are:

With the command “show interfaces terse” I can see a list of the available interfaces on my Juniper router.

Let me show you how you can restart your Juniper router as well.

Using this command, you can simply reboot your Juniper router and this is done from the Operational mode.

The last thing that I want to show you in this topic is the configuration mode. As I said, on this mode you can do the configuration on the Juniper router. To go from the operational mode to the configuration mode, you need to write any of the following 2 commands:

• Edit
• Configure

I will write “edit” and see if I can go to the configuration mode:

I am in the configuration mode 😊

Let’s do a simple task by just changing the name of the router from R1 to R2 and see if it works.

Don’t forget to save your configuration after you make the changes so it is applied. I can see clearly that the router name has been changed successfully to R2.

That’s all what I wanted to explain about the different modes on Juniper. I have showed you also different LABs on each mode so you can understand it better 😊.