Permanent Interfaces

Each routing platform uses multiple permanent interfaces as follows:

• Management Ethernet interface—For M-series, T-series, and MX-series routing platforms, the JUNOS software automatically creates the routing platform’s management Ethernet interface, fxp0. The management Ethernet interface provides an out-of-band method for connecting to the routing platform. To use fxp0 as a management port, you must configure its logical port, fxp0.0, with a valid IP address. You can connect to the management interface over the network using utilities such as ssh and telnet. Simple Network Management Protocol (SNMP) can use the management interface to gather statistics from the routing platform.
• For the J-series Services Routers, you can use any of the built-in Ethernet ports as a management interface. To use a built-in interface as a management Ethernet interface, configure it with a valid IP address. The factory configuration for the J4350 and J6350 Services Routers automatically enables the J-Web user interface on the ge-0/0/0, ge-0/0/1, ge-0/0/2, and ge-0/0/3 interfaces. To manually configure J-Web access, include the interface interface-name statement at the [edit system services web-management http] hierarchy level. For information about establishing basic connectivity and configuring a management port, see the Getting Started guide for your router.
• Internal Ethernet interface—The JUNOS software creates the internal Ethernet interface fxp1. The internal Ethernet interface connects the Routing Engine re0 (the portion of the routing platform running the JUNOS software) to the Packet Forwarding Engine. If the routing platform has redundant Routing Engines, another internal Ethernet interface, fxp2, is created on each Routing Engine (re0 and re1) in order to support fault tolerance. Two physical links between re0 and re1 connect the independent control planes. If one of the links fails, both Routing Engines can use the other link for IP communication.

The JUNOS software boots the packet forwarding component hardware. When these components are running, the control board uses the internal Ethernet interface to transmit hardware status information to the JUNOS software. Information transmitted includes the internal routing platform temperature, the condition of the fans, whether an FPC has been removed or inserted, and information from the craft interface on the LCD panel. The internal Ethernet interface is configured automatically when the JUNOS software boots.

Each routing platform also has two serial ports, labeled console and auxiliary, for connecting tty-type terminals to the routing platform using standard PC-type tty cables. Although these ports are not network interfaces, they do provide access to the routing platform.

Copyright © 2009, Juniper Networks, Inc. All rights reserved. Trademark Notice.