Initial Router Configuration Using the Junos OS
This topic provides an overview of initial router configuration tasks using the Junos OS.
On most Junos routers, the Junos OS is installed on the CompactFlash card and on the hard disk. When you first turn on a router, it runs the version of the Junos OS installed on the CompactFlash card. The copy of Junos OS on the hard disk is a backup. Another backup copy of the Junos OS is available on removable media, such as a PC Card or a CompactFlash card. Be sure to put the backup Junos OS (on removable media) in a safe place.
When you turn on a router the first time, the Junos OS automatically boots and starts. You must enter basic configuration information so that the router is on the network and you can log in to it over the network.
To configure the router initially, you must connect a terminal or laptop computer to the router through the console port—a serial port on the front of the router. Only console access to the router is enabled by default. Remote management access to the router and all management access protocols, including Telnet, FTP, and SSH, are disabled by default.
When you first connect to the router 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 router 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 the Junos OS operational mode. Enter the 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, you must configure the following basic properties:
- Router hostname
- Domain name
- IP address of the router Ethernet management interface—On
all routers other than the TX Matrix Plus router and the T1600 routers
in a routing matrix, the management Ethernet Interface is fxp0. On a TX Matrix Plus router and the T1600 routers in a routing matrix,
the management Ethernet interface is em0.
Note: The management Ethernet interface created on a T1600 standalone router (not part of routing matrix and not connected to a TX Matrix Plus router) continues to be fxp0 and not em0. The em0 management Ethernet interface is only applicable for a TX Matrix Plus router and T1600 routers connected to a TX Matrix Plus router in a routing matrix.
- IP address of a backup router
- IP address of one or more DNS name servers on your network
- Password for the root account
