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SRX4120 Ports and Interfaces

This topic describes the ports on the SRX4120 and their corresponding Junos OS interfaces.

Interface Naming on the SRX4120

The ports on the SRX4120 have interfaces associated with them in Junos OS. These interfaces follow the below naming convention:

type-fpc/pic/port:channel

  • type—This refers to the media type of the interface. For some interfaces, the media type depends on the transceiver plugged into the physical port.

    • ge—1 Gigabit Ethernet (GbE) interface

    • xe—10 GbE interface

    • mge—1/2.5/5/10 GbE Multirate Gigabit Ethernet interface

    • et—25/40/100 GbE interface

  • fpc—Flexible PIC Concentrator. On the SRX4120, FPC number is 0.

  • pic—Physical Interface Card. On the SRX4120:

    • PIC 0 consists of eight multirate RJ-45 ports.

    • PIC 1 consists of eight SFP+ ports.

    • PIC 2 consists of four SFP28 ports.

    • PIC 3 consists of two QSFP28 ports.

  • port—You can check the port number from the front panel of the SRX4120.

  • channel—This is only applicable to channelized interfaces. For all other interfaces, this option is absent.

Network Ports on the SRX4120

Table 1: SRX4120 Network Ports
Form Factor Port Component Port Count Speeds Supported FPC PIC Junos Interfaces

RJ-45

Multirate Gigabit Ethernet

8

1/2.5/5/10 G

0

0

mge-0/0/0 to mge-0/0/7

SFP+

SFP/SFP+

8

1/10 G

0

1

1G: ge-0/1/0 to ge-0/1/7

10G: xe-0/1/0 to xe-0/1/7

SFP28

SFP/SFP+/SFP28

4

1/10/25 G

0

2

1G: ge-0/2/0 to ge-0/2/3

10G: xe-0/2/0 to xe-0/2/3

25G: et-0/2/0 to et-0/2/3

QSFP28

QSFP/QSFP28

2

 4x10/4x25/2x50/40/100 G

0

3

et-0/3/0 to et-0/3/1

See the Hardware Compatibility Tool for a list of all supported optics for the SRX4120.

Note:

The BASE-T PIC 0 ports support autonegotiation. The SFP+ PIC 1 ports support 1 GbE SFP-T but do not support autonegotiation. The SFP28 PIC 2 ports and QSFP28 PIC 3 ports do not support SFP-T or autonegotiation.

Interfaces on the SRX4120

Each network port on the SRX4120 has a unique interface on Junos OS associated with it.

The interfaces for all PIC 0 ports are already created. The interfaces for PIC 1, PIC 2, and PIC 3 ports are created when you insert a transceiver into the respective port. PIC 1 and PIC 3 interfaces automatically determine the interface speed from the type of transceiver plugged into the port. PIC 2 interfaces are automatically created when using a 25G transceiver. When using a 10G/1G transceiver, you need to manually configure the interface speed using the CLI.

The example below shows the actual hardware or transceivers plugged into a device and how Junos OS creates the corresponding interfaces. The output has been truncated to only show the relevant sections.

In this example:

  • The interfaces for PIC 0 ports are automatically created (mge-0/0/0 to mge-0/0/7).

  • PIC 1 has three 10G transceivers plugged into ports 0 through 2. Junos OS creates corresponding 10G interfaces (xe-0/1-0 to xe-0/1/2).

  • PIC 2 has two 10G and two 1G transceivers plugged into it. Without explicit configuration, Junos OS does not identify these interface speeds and so does not create the PIC 2 interfaces.

  • There are no transceivers plugged into PIC 3.