JUNOS High Availability

Chapter 3. Software High Availability

In many networks, there seems to be a very clear divide in administration levels between those who consider themselves server experts and those who consider themselves networking experts. The problem is that the actual pieces of our networking equipment are merely computers designed specifically to pass traffic as quickly as possible. Though a network engineer does not require the knowledge to recompile kernels in order to maintain high availability in his network, he should have at least a basic understanding of how the operating system software that is running on his network equipment is designed.

By understanding how JUNOS software is designed and operates on your equipment, you are able to more accurately plan and prepare for critical situations, such as network-wide software upgrades, when high availability needs to be maintained. These are the times when the software is placed under the greatest strain.

This chapter provides an overview of the software design decisions and the software architecture of JUNOS devices, for it is the JUNOS software that provides the stable software foundation for the control of resilient and redundant hardware.