Junos Os Processes - Dell PowerConnect J-EX4200-24T Software Manual

Junos OS Processes

Table 20: Junos OS Processes
Process Name
Chassis process chassisd
Ethernet eswd
switching
process
Forwarding pfem
process
Interface dcd
process
Management mgd
process
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 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 Junos OS, for added flexibility.
Table 20 on page 23 describes the primary Junos OS processes.
Description
Detects hardware on the system that is used to configure network interfaces.
Monitors the physical status of hardware components and field-replaceable units
(FRUs), detecting when environment sensors such as temperature sensors are triggered.
Relays signals and interrupts—for example, when devices are taken offline, so that the
system can close sessions and shut down gracefully.
Handles Layer 2 switching functionality such as MAC address learning, Spanning Tree
protocol and access port security. The process is also responsible for managing Ethernet
switching interfaces, VLANs, and VLAN interfaces.
Manages Ethernet switching interfaces, VLANs, and VLAN interfaces.
Defines how routing protocols operate on the switch. The overall performance of the
switch is largely determined by the effectiveness of the forwarding process.
Configures and monitors network interfaces by defining physical characteristics such
as link encapsulation, hold times, and keepalive timers.
Provides communication between the other processes and an interface to the
configuration database.
Populates the configuration database with configuration information and retrieves the
information when queried by other processes to ensure that the system operates as
configured.
Interacts with the other processes when commands are issued through one of the user
interfaces on the switch.
If a process terminates or fails to start when called, the management process attempts
to restart it a limited number of times to prevent thrashing and logs any failure
information for further investigation.
Chapter 1: Software Overview
23