Single OS code base across multiple platforms Different
platforms use different binary images Modular OS Based on FreeBSD
Installed OS package, not single binary file
Junos Release Schedule
Example: junos-srxsme-11.4R9.4-domestic.tgz
Quarterly Releases New Services and Features 10.1, 11.2, 13.3
Feature / bug fix roll-up
Revision Releases R1 = initial release R2, R3, etc. = bug fixes
Decimal number = build ID
Extended End of Life (EEOL) Releases Last major release of each
year Supported for 3 years from first released shipment (FRS)
date
36 months end of engineering (EOE) + 6 months end of life (EOL)
JTAC recommended software versions
Junos Architecture
Junos kernel Supports user processes Maintains forwarding table
synchronization between routing engine (RE)
and packet forwarding engine (PFE) Provides interface related
routing functions
Separate daemons in protected memory space Routing protocol
process Interface control process Management processes (SNMP, LLDP,
etc.)
Common command syntax
Separation of Duties
Control Plane - Routing Engine (RE) Forwarding Plane - Packet
Forwarding Engine (PFE) Forwarding table maintained on RE and
synchronized to the PFE
through the kernel
The Control Plane
Routing engine or CPU Responsible for device management
Maintains routing table Protocol updates Maintains primary
forwarding table
The Forwarding Plane
Focuses on forwarding of traffic Implemented in Application
Specific Integrated Circuits (ASICs) Relies on synchronized copy of
forwarding table from RE
Interacting with Junos
Command Line Interface (CLI) Web Interface (J-Web) APIs
Junos Space Puppet NETCONF
Summary
Junos is single code base and command syntax Quarterly software
releases with yearly extended support release Modular OS with
separate memory spaces Control plane (RE) for management Forwarding
plane (PFE) dedicated to traffic forwarding Access via CLI,
web-interface, or APIs
Introduction to the Junos OSJunosJunos Release ScheduleJunos
ArchitectureSeparation of DutiesThe Control PlaneThe Forwarding
PlaneInteracting with JunosSummary
