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Initial Router or Switch Configuration Using Junos OS


This topic provides an overview of initial router or switch configuration tasks using Junos OS.

When you turn on a router or switch for the first time, Junos OS automatically boots and starts. You must enter basic configuration information so that the router or switch is on the network and you can log in to it over the network.

To configure the router or switch initially, you must connect a terminal or laptop computer to the router or switch through the console port—a serial port on the front of the router or switch. Only console access to the router or switch is enabled by default. Remote management access to the router or switch and all management access protocols, including Telnet, FTP, and SSH, are disabled by default.

When you first connect to the router or switch console, you must log in as the user root. At first, the root account requires no password. You see that you are the user root, because the command prompt shows the username root@#.

You must start the Junos OS command-line interface (CLI) using the command cli. The command prompt root@> indicates that you are the user root and that you are in Junos OS operational mode. Enter Junos OS configuration mode by typing the command configure. The command prompt root@# indicates that you are in the Junos OS configuration mode.

When you first configure a router or switch, you must configure the following basic properties:

  • Router or switch hostname

  • Domain name

  • IP address of the router or switch management Ethernet interface. To find the management Ethernet interface that you should use for configuration, see Supported Routing Engines by Router.

  • IP address of a backup router

  • IP address of one or more DNS name servers on your network

  • Password for the root account