JUNOS Software Processes

Management process

mgd

Manages the Services Router system as follows:

• 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 router

Chassis process

chassisd

Controls a Services Router chassis and its components as follows:

• 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

Routing protocol process

rpd

Defines how routing protocols such as RIP, OSPF, and BGP operate on the router, including selecting routes and maintaining fowarding tables.

Interface process (also called device control process)

dcd

Supplies the programs that configure and monitor network interfaces by defining physical characteristics such as link encapsulation, hold times, and keepalive timers.

Forwarding process

fwdd

Responsible for most of the packet transmission through a Services Router. The overall performance of the router is largely determined by the effectiveness of the forwarding process.