line console command (2024)

I believe that it would help if we think about the various parameters in the command one at a time:

1) line. This parameter specifies that we will be configuring some type of access port. Note that there can be multiple types of access ports including console, aux, and vty. The line command requires 2 additional parameters.

2) console. This parameter specifies that we will be configuring access via the console port.

3) 0. This parameter specifies which (if there are alternatives) port we will be configuring. Since there is physically only a single console port we always use 0 for the console and the parameter is almost superfluous. But the line command requires 2 additional parameters be input and we must use something here. This parameter is essential if we are configuring the vty and trivial if we are configuring the console.