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Step 2: Up and Running


Now that the QFX5120 is powered on, let’s do some initial configuration to get it up and running on the network. It’s simple to configure and manage the QFX5120 using the CLI.

Plug and Play

The QFX5120 switch ships with factory-default settings that enable plug-and-play operation. These settings load as soon as you power on the switch.

Customize the Basic Configuration

You can easily customize the factory-default configuration with just a few commands. When you commit changes to the configuration, a new configuration file is created. This becomes the active configuration. You can always revert to the factory-default configuration anytime you want.

Have the following information ready before you begin customizing the switch:

  • Root authentication password

  • Management port IP address

  • Default gateway IP address

  • DNS server IP address

  1. Verify that your laptop or desktop PC has the following default serial port settings:
    • Baud Rate—9600

    • Data—8

    • Flow Control—None

    • Parity—None

    • Stop Bits—1

    • DCD State—Disregard

  2. Connect the console port (labeled CON) on the QFX5120 switch to a serial port on your laptop or desktop PC using the Ethernet cable and RJ-45 to DB-9 adapter. If your laptop or desktop PC doesn't have a serial port, use a serial-to-USB adapter (not provided).
  3. At the Junos OS login prompt, type root to log in. You don't need to enter a password. If the software boots before you connect your laptop or desktop PC to the console port, you might need to press the enter key for the prompt to appear.
  4. Start the CLI.
  5. Enter the configuration mode.
  6. Add a password to the root administration user account. Enter a plain-text password, an encrypted password, or an SSH public key string.

    Plain-text password:

    Encrypted password:

    SSH-ECDSA password:

    SSH-ED25519 password:

    SSH-RSA password:

  7. Configure the default gateway.
  8. Configure the IP address and prefix length for the management interface on the switch.

    The management port em0 (labeled MGMT) is on the rear panel of the QFX5120-48T switch. The management ports em0 (labeled C0) and em1 (labeled C1) are on the rear panel of the QFX5120-48Y and QFX5120-48YM switches.

    The management interface provides a dedicated out-of-band management channel to manage devices on the network. If you need to configure in-band management, see Configure Junos OS on the QFX5120 in the QFX5120 Switch Hardware Guide.

  9. Configure the IP address of a DNS server.
  10. Configure the SSH service.
  11. Commit the configuration to activate it on the switch.
  12. When you’ve finished configuring the switch, exit the configuration mode.