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Step 1: Begin

In this guide, we provide a simple, three-step path, to quickly get you up and running with your new EX4300. We’ve simplified and shortened the installation and configuration steps, and included how-to videos. You’ll learn how to install an AC-powered EX4300, power it up, and configure basic settings.


Are you interested in getting hands-on experience with the topics and operations covered in this guide? Visit Juniper Networks Virtual Labs and reserve your free sandbox today! You’ll find the Junos Day One Experience sandbox in the stand alone category. EX switches are not virtualized. In the demonstration, focus on the virtual QFX device. Both the EX and QFX switches are configured with the same Junos commands.

Meet the EX4300 Line of Ethernet Switches

The Juniper Networks® EX4300 Ethernet Switches are fixed-configuration platforms that can be deployed as standalone systems or as part of a Virtual Chassis switching architecture. The EX4300 switches are available in 24-port, 32-port, and 48-port models, with or without PoE+, with AC or DC power supplies, and with different airflow directions. EX4300 switches also provide uplink ports and a slot for installing an optional uplink module.


10/100/1000BASE-T Ports

PoE/PoE+ Ports















(plus 24 100/1000/2500/5000/10000BASE-T ports)



32 100/1000BASE-X ports


In this guide, we show you how to install an AC-powered EX4300 switch with the fan modules and power supplies preinstalled. If you need instructions for installing fans, power supplies, and optional uplink modules, see the EX4300 Switch Hardware Guide.

Install the EX4300

You can install the EX4300 switch on a table or desktop, on a wall, or in a two-post or four-post rack. The mounting kit that ships in the box has the brackets you need to install the EX4300 switch in a two-post rack. We’ll walk you through how to do that.


If you want to install the switch on the wall or in a four-post rack, you’ll need to order separate mounting kits. The four-post rack mount kit also has brackets for mounting the EX4300 switch in a recessed position in the rack.

What’s in the Box?

  • EX4300 switch

  • An AC power cord appropriate for your geographical location

  • Two mounting brackets and eight mounting screws

What Else Do I Need?

You’ll need to provide the following:

  • Four rack mount screws to secure the chassis to the rack

  • A number two Phillips (+) screwdriver

  • An electrostatic discharge (ESD) grounding strap

  • A management host such as a laptop or desktop PC

  • A serial-to-USB adapter (if your laptop or desktop PC doesn’t have a serial port)

  • Someone to help you secure the switch to the rack

  • An Ethernet cable with RJ-45 connectors attached and an RJ-45 to DB-9 serial port adapter


    We no longer include the RJ-45 console cable with the DB-9 adapter as part of the device package. If the console cable and adapter are not included in your device package, or if you need a different type of adapter, you can order the following separately:

    • RJ-45 to DB-9 adapter (JNP-CBL-RJ45-DB9)

    • RJ-45 to USB-A adapter (JNP-CBL-RJ45-USBA)

    • RJ-45 to USB-C adapter (JNP-CBL-RJ45-USBC)

    If you want to use RJ-45 to USB-A or RJ-45 to USB-C adapter you must have X64 (64-Bit) Virtual COM port (VCP) driver installed on your PC. See, to download the driver.

Install the EX4300 Switch in a Two-Post Rack

  1. Review General Safety Guidelines and Warnings
  2. Wrap and fasten one end of the ESD grounding strap around your bare wrist, and connect the other end to a site ESD point.
  3. Attach the mounting brackets to the sides of the EX4300 switch using the eight screws and a screwdriver.

    You’ll notice there are three locations on the side panel where you can attach the mounting brackets: front, center, and rear. Attach the mounting brackets to the location that best suits where you want the EX4300 switch to sit in the rack.

  4. Lift the EX4300 switch and position it in the rack. Line up the bottom hole in each mounting bracket with a hole in each rack rail, making sure the EX4300 switch is level.
  5. While you’re holding the EX4300 switch in place, have someone insert and tighten the rack mount screws to secure the mounting brackets to the rack rails. Make sure to tighten the screws in the two bottom holes first and then tighten the screws in the two top holes next.
  6. Check that the mounting brackets on each side of the rack are level.

Power On

Now you’re ready to connect the EX4300 switch to a dedicated AC power source. The switch comes with the AC power cord for your geographic location.

Here’s how to connect the EX4300 switch to AC power:

  1. Wrap and fasten one end of an ESD wrist strap around your bare wrist, and connect the other end of the strap to the ESD point on the switch.
  2. On the rear panel, connect the retainer clip and power cord to the AC power socket (see Figure 1 and Figure 2):
    1. Push the end of the retainer strip into the hole next to the AC power socket until it snaps into place.
    2. Press the small tab on the retainer strip to loosen the loop.
    3. Slide the loop until you have enough space to insert the power cord coupler into the AC power socket.
    4. Plug in the power cord to the power socket on the switch.
    5. Slide the loop toward the power supply until it is snug against the base of the coupler.
    6. Press the tab on the loop and draw out the loop into a tight circle.
    Figure 1: Connecting AC Power to an EX4300 Switch (Except the EX4300-48MP)Connecting AC Power to an EX4300 Switch (Except the EX4300-48MP)
    Figure 2: Connecting Power to an EX4300-48MP SwitchConnecting Power to an EX4300-48MP Switch
  3. If the AC power source outlet has a power switch, turn it off.
  4. Plug in the AC power cord to the AC power source outlet.
  5. If the AC power source outlet has a power switch, turn it on.
  6. Check to see that the IN OK and the OUT OK LEDs on each power supply are lit green.

    If the OUT OK LED is lit amber, turn off the AC power source outlet or unplug the switch. You’ll need to replace the power supply. See Removing an AC Power Supply from an EX4300 System.