If you are new to Juniper and having a hard time figuring out what the ports are called on an EX4100-F-12P.

Check the hardware components of your switch, and look at the following:

- The amount of PICs.

- The amount of ports per PIC.

- The speed they are capable to run at.
 

1- This is what the PICs on this platform are:

2- Here's what the PICs allow the ports speed to run at:

 PIC 0    <--- 12x ports at 10m/100m/1g

 PIC 1    <--- 4x ports at 1g/10g

 PIC 2    <--- 2x ports at 1g/2.5g/5g/10g
 

Ports on PIC 0 are named ge-0/0/[0-12]

Ports on PIC 1 are named ge-0/1/[0-3] or xe-0/1/[0-3]

Ports on PIC 2 are named mge-0/2/[0-1]