JUNOS Enterprise Switching

JUNOS Software Overview

To quote from JUNOS Enterprise Routing:

JUNOS software is cool. It just is. The designers of JUNOS software put tremendous thought into making a stable, robust, and scalable operating system that would be a positive for the router. They were able to learn from previous vendors’ mistakes, and create an OS that other companies will forever use as their model.

JUNOS software is cool, and the fact that the same JUNOS software that runs on the EX platform runs on the largest router that Juniper makes, the TX Matrix, is really cool.

JUNOS software is a modular operating system that promotes stability and reliability. The modularization is achieved through the use of software daemons that run in protected memory space. The stability stems from well-written and tested code; choosing a well-known, open source, and stable kernel of FreeBSD on which to build JUNOS did not hurt, of course.

The kernel and its functions are normally not directly visible to the user, but many features of FreeBSD have been ported to the command line of JUNOS, and many that have not are still available, albeit at the shell prompt. The kernel supports the various user processes (daemons), maintains the forwarding table synchronization between the RE and the PFE, and provides interface-related routing functions such as performing ARP and installing local and direct routes in the routing table (RT).

Riding on top of the kernel are the software processes that provide JUNOS services and the user interfaces ...