Discussion

Preface1
Over the past decade, network service providers have been adding high-performance
Juniper Networks routers to their networks to run their IP backbones. With the
recent introduction of smaller routers with the same basic functionality as the larger
core routers, more people will be using Juniper Networks routers in their business
networks and will need to learn how to configure and run the JUNOS software that
runs on their routers. JUNOS Cookbook explains the design of the JUNOS software
and provides recipes and guidelines for setting up common features that you need to
configure and secure your Juniper Networks router.
For those of you who are familiar with Cisco IOS or other routers, you will find the
JUNOS software and the design of the router hardware similar to the other routers in
some ways, but very different in many ways. The initial design of the JUNOS software
began in 1996, when the TCP/IP protocol suite was already mature and it was
clear that this protocol suite was the only one needed for network devices to run on
the Internet. Those involved in developing the original JUNOS software and router
hardware all had previous experience designing similar products and were intent on
building something better. Some of the JUNOS features that improve the router
operation include:
Software modularity
The JUNOS software comprises several dozen processes, or daemons, rather
than a single process, so you can stop a single process and restart it without
having to reboot the entire router.
Separation of forwarding and routing
The actual forwarding of packets is performed by custom high-speed Application-
Specific Integrated Circuits (ASICs), while routing is performed by a CPU in a
small PC that is built into the router. This separation of the routing and forwarding
functions improves router performance.
This is the Title of the Book, eMatter Edition
Copyright © 2008 O’Reilly & Associates, Inc. All rights reserved.
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