(for configuring, monitoring, managing, and troubleshooting devices running this OS)
The Junos CLI is a text-base command shell like many others, in fact it remembers me the CLI from Ontap, as both are based on FreeBSD.
There are two options to access the CLI:
out-of-band (OoB) serial console connection
over the network (in band) using access protocol SSH
Regarding the J-Web Interface is the classic web-based interface gui that you can access on any browser. It is intuite and easy to use as it simplify most configurations tasks.
Curiosity: One thing about the hostname it is that as factory-default configuration the hostname displayed it will be Amnesiac.
Anazling deeper the Junos CLI have two modes:
The Operational Mode allows you to use the CLI for monitoring and troubleshooting.
The Configuration Mode is more suitable for admins as this option allow you to configure all properties of Junos OS, including interfaces, protocols, user access and also some system hardware properties.
Useful stuff: If you type ? aywhere on the command like you will receive help on which commands you could use. Also it will be handy to remember that if you type Tab key it will show you complete commands and variables. Plus if you do not remember how to finalize a command or which options do you have, an alternative to Tab key, it is to type ? and press enter during the command so it will suggest you which other posibilities do you have.
Types of help commands:
help topic interfaces? -> display usage guidelines for the statement
help reference interfaces address -> display summary information for the referenced configuration statement