Juniper JUNOS OS 10.3 - SOFTWARE, Руководство пользователя

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Understanding Software Infrastructure and Processes
Each switch runs the Juniper Networks Junos operating system (Junos OS) for Juniper
Networks EX Series Ethernet Switches on its general-purpose processors. Junos OS
includes processes for Internet Protocol (IP) routing and for managing interfaces,
networks, and the chassis.
The Junos OS runs on the Routing Engine. The Routing Engine kernel coordinates
communication among the Junos OS processes and provides a link to the Packet
Forwarding Engine.
With the J-Web interface and the command-line interface (CLI) to the Junos OS, you
configure switching features and routing protocols and set the properties of network
interfaces on your switch. After activating a software configuration, use either the J-Web
or CLI user interface to monitor the switch, manage operations, and diagnose protocol
and network connectivity problems.
• Routing Engine and Packet Forwarding Engine on page 23
• Junos OS Processes on page 23
Routing Engine and Packet Forwarding Engine
A switch has two primary software processing components:
• Packet Forwarding Engine—Processes packets; applies filters, routing policies, and
other features; and forwards packets to the next hop along the route to their final
destination.
• Routing Engine—Provides three main functions:
• Creates the packet forwarding switch fabric for the switch, providing route lookup,
filtering, and switching on incoming data packets, then directing outbound packets
to the appropriate interface for transmission to the network
• Maintains the routing tables used by the switch and controls the routing protocols
that run on the switch.
• Provides control and monitoring functions for the switch, including controlling power
and monitoring system status.
Junos OS Processes
The Junos OS running on the Routing Engine and Packet Forwarding Engine consists of
multiple processes that are responsible for individual functions.
The separation of functions provides operational stability, because each process accesses
its own protected memory space. In addition, because each process is a separate software
package, you can selectively upgrade all or part of the Junos OS, for added flexibility.
Table 17 on page 24 describes the primary Junos OS processes.
23 Copyright © 2010, Juniper Networks, Inc.
Chapter 1: Software Overview