What does the number ‘’2’’ indicate in interface ge—0/1/2?

In the Junos OS interface naming convention, the format is type-fpc/pic/port. For the interface ge-0/1/2, ge represents the media type (Gigabit Ethernet). The first number, 0, indicates the Flexible PIC Concentrator (FPC) slot. The second number, 1, indicates the Physical Interface Card (PIC) slot within the FPC. The third and final number, 2, specifies the physical port number on that specific PIC. Therefore, '2' represents the port number.

A. The interface logical number: The logical unit number is appended after the physical interface name, separated by a period (e.g., ge-0/1/2.0).
B. The physical interface card (PIC): The PIC is represented by the second number in the sequence, which is '1' in this example.
D. The flexible PIC concentrator (FPC): The FPC is represented by the first number in the sequence, which is '0' in this example.

1. Juniper Networks TechLibrary

Junos OS

"Interface Naming Overview". This official documentation explicitly defines the type-fpc/pic/port structure. It states

"port—Port number on the PIC."

URL: https://www.juniper.net/documentation/us/en/software/junos/interfaces-fundamentals/topics/concept/interfaces-naming-overview.html

2. Juniper Networks

Day One: Junos for Beginners

2nd Edition

Chapter 2

"The Junos OS Command-Line Interface". This guide explains the interface naming convention

confirming that the third number in the triplet identifies the port.

URL: https://www.juniper.net/us/en/training/jnbooks/day-one/networking-technologies-series/junos-for-beginners.html (PDF available for download

see section on "Interface Names")