Juniper Operating System
Fundamental for APNIC
Training Lab
APNIC Technical Workshop
Acknowledgment
• APNIC training lab facilitate hands-on training and
workshop requirement for APNIC community in AP region. • APNIC training continues its best effort to support multi
vendor/open standard technology and software when deliver hands-on training.
• This presentation is prepared to support JunOS specific hands-on lab exercises in APNIC training lab.
Overview
• JunOS Operating System Fundamental • JunOS User Interface and CLI
• Basic & Interface Configuration on APNIC Training Lab • JunOS Routing Fundamentals & Policy Control
JunOS Fundamental
• Robust, Modular and Scalable • Single Source Code Base
Robust, Modular and Scalable
• Run multiple software process. • Each process controls a portion of
device hardware functionality. • Each process runs in its own
protected memory space so one
process cannot directly interfere with another.
Single Source Code Base
• The JunOS kernel is based on the open source FreeBSD UNIX operating system.
• All Juniper device running the same JunOS use the same software source code base within their platform-specific images.
• It ensures core features work consistently across all platforms running the JunOS.
Separate Control & Forwarding Plane
• The processes that control the routing & switching protocol parameter and forwards data frames are clearly separated in JunOS devices.
• Forwarding plane functions are mostly done based on the application-specific integrated circuits (ASICs) for
increased performance.
• This design allows to tune each process for maximum performance and reliability.
Separate Control & Forwarding Plane
Routing Engine (RE)
• The control plane runs on the Routing Engine (RE) that is the brain of the device. It is responsible for performing protocol updates and system
management functions.
• RE is mainly based on X86 or PowerPC architecture, depending on the specific platform and it runs various protocol and management software processes that reside inside a protected memory environment.
Separate Control & Forwarding Plane
Packet Forwarding Engine (PFE)
• PFE receives the forwarding table (FT) from the RE by means of an internal link and simply forwards frames, packets, or both with a high degree of
stability and deterministic performance.
• The PFE usually runs on separate hardware / in many case application-specific integrated circuits (ASICs) and is responsible for forwarding transit traffic through the device.
Separate Control & Forwarding Plane
Forwards Traffic
• The PFE is the central processing component of the forwarding plane.
• The PFE forwards traffic based on its local copy of the forwarding table created by a regular synchronization with the RE.
Traffic Processing Behaviour
Transit Traffic
• Transit traffic defined as the traffic enters an ingress network port, compared against the forwarding table entries, and is forwarded out an egress network port toward the final destination.
• For transit traffic a forwarding table entry must be exist to successfully forward transit traffic to that destination.
• Transit traffic passes through the forwarding plane only and is never sent to or processed by the control plane.
Traffic Processing Behaviour
Exception Traffic:
• Exception traffic is defined as the traffic does not pass through the local device. It is destined to the local device and require special handling. I.e.
– Packet addressed to the chassis, such as routing update packets, telnet/ssh session to the device replies to the transit source.
– IP packet with IP option field. PFE are not purposely designed to process IP option field.
– Traffic that requires the generation of Internet Control Message Protocol (ICMP) messages.
Traffic Processing Behaviour
Built-in Rate Limit for Exception Traffic:
• In JunOS all exception traffic destined to RE are sent through an “Internal Link” which connects the RE and PFE.
• JunOS has a hardware based rate limiting on the internal link that protects the JunOS device RE from any potential DoS attacks. • During the time of congestion JunOS device gives preference to
local and control traffic destine to RE.
Appendix Slides
Juniper Product Range
Three Type of Equipment:
• Routing Devices • Switching Device
JunOS User Interface
and CLI
JunOS CLI Introduction
Switch Between Different Mode:
JunOS CLI Introduction
Type “?” to get Available Command from the Hierarchy:
root> configure ?
Possible completions:
<[Enter]> Execute this command batch Work in batch mode
dynamic Work in dynamic database exclusive Obtain exclusive lock
JunOS CLI Introduction
Execute Command from Different Hierarchy:
JunOS CLI Introduction
Execute Command from Different Hierarchy:
JunOS CLI Introduction
Save Configuration and Exit:
[edit]
root@Router21# commit and-quit root@Router21>
JunOS CLI Introduction
Check the Rollback & Restore:root# rollback ?
Possible completions:
<[Enter]> Execute this command
0 2015-06-17 12:37:31 UTC by root via cli 1 2015-06-17 12:35:15 UTC by root via cli 2 2015-06-17 12:34:33 UTC by root via cli rescue 2015-06-17 12:36:00 UTC by root via cli [edit]
JunOS CLI Introduction
To get a Unix shell:
root@Router21> start shell
[will support standard unix command line]
Switch to JunOS CLI:
root@Router21% cli
[Come back to JunOS command line]