Specifications

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Command-line Interface
Kernel
Intel-based PIC platform
System
Management
Processes
Routing
Protocols
Control
Functions
JUNOS Software
Routing Engine
Routing Engine and JUNOS Software Architecture
The Routing Engine connects directly to the Packet Forwarding Engine. This
separation of routing and forwarding performance ensures that the Routing
Engine never processes transit packets. Of the traffic that goes to the Routing
Engine, link-level keepalives and routing protocol updates receive the highest
priority to ensure that adjacencies never go down regardless of the load, thereby
preventing failures from cascading through the network.
Additionally, the JUNOS software passes incremental changes in the forwarding
tree to the Packet Forwarding Engine so that high rates of change are quickly and
cleanly handled. Together, the nearly instantaneous routing updates and the
JUNOS software ensure that the Packet Forwarding Engine continues to forward
packets at wire rate during times of heavy route fluctuations.
Software Processes
JUNOS software consists of the following processes that control router
functionality and a kernel that provides the communication among all the
processes.
Routing Protocol Process
The JUNOS software implements full IP routing functionality, providing support
for IPv4. The routing protocols are fully interoperable with existing IP routing
protocols and provide the scale and control necessary for the backbone core and
edge.
Interface Process
The JUNOS interface process enables you to configure and control the physical
and logical interfaces. You can configure interfaces that are currently in the
router, as well as those that you plan to add in the future. You can also configure
interface properties, such as in which location on the Flexible PIC Concentrator
(FPC) the Physical Interface Card (PIC) is installed, in which slot the FPC is
installed, the interface encapsulation, and interface-specific properties.
Chassis Process
The JUNOS chassis process enables you to configure and control the properties
of the router, including conditions that trigger alarms and clock sources. This
process communicates directly with a chassis process in the JUNOS kernel.
SNMP and MIB II Processes
The JUNOS software includes SNMP software, which helps with monitoring the
state of a router. SNMP software consists of an SNMP master agent and a MIB II
agent; it supports MIB II SNMP version 1 traps and version 2 notifications.
Management Process
The management process starts and monitors all other software processes, as
well as starts the CLI, which is the primary tool for controlling and monitoring the
software. This process automatically starts all other software processes and the
CLI when the router boots. If a software process terminates, the management
process attempts to restart it.