Understanding Software Infrastructure And Processes - Juniper JUNOS OS 10.4 - FOR EX REV 1 Manual

Complete Software Guide for Junos

Understanding Software Infrastructure and Processes

Routing Engine and Packet Forwarding Engine
Junos OS Processes
26
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OS for EX Series Ethernet Switches, Release 10.4
Understanding VRRP on EX Series Switches on page 1172
Understanding Aggregated Ethernet Interfaces and LACP on page 1244
Understanding Nonstop Active Routing on EX Series Switches on page 1175
Understanding Nonstop Software Upgrade on EX Series Switches on page 1176
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 26
Junos OS Processes on page 26
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.
The Junos OS running on the Routing Engine and Packet Forwarding Engine consists of
multiple processes that are responsible for individual functions.
Copyright © 2010, Juniper Networks, Inc.