What You Should Know about Upgrading Junos
A topic essential to operating your network is software upgrades. The delivery model of new Junos releases simplifies the process of upgrading compared to other networking systems.
New releases and numbers
Juniper ships new major versions of the Junos OS to deliver new features and functionality to its customers three to four times per year.
Junos releases are numbered according to a year.sequence convention. For example, the last release of 2011 is 11.4 and the first release in 2012 will be 12.1. You can determine the release version from the release package name. For example:
jinstall-ex-4200 is the descriptor of the release platform, in this example the EX4200.
11.2 is the major version number (the second release of the year in 2011).
R is the type of release. In this example, the R designates a shipped release. Other types are S for service release and B for a Beta release.
2 is the revision number — that is, the numbered sequence of the maintenance releases, where the First Release Shipment (FRS) is always R1.
4 is the build number of the release and may be requested by Juniper Networks Technical Assistance Center (JTAC) during service discussions.
domestic-signed indicates that the software is for use in the U.S. and Canada. The other type is worldwide, designated by export-signed.
Maintenance and service releases
Following the availability of any major Junos OS version, Juniper also issues maintenance and service releases to deliver needed fixes to that shipping version throughout its support life.
Maintenance releases: Standard releases to provide fixes in shipped and supported version releases. The software download page links to the latest revision available for each currently supported Junos OS version.
Service releases: Targeted releases to provide more timely delivery of critical fixes to meet customer needs. Service releases may be limited to specific platforms or use cases. Juniper constrains the scope of the fixes to only critical fixes. The service releases are available through JTAC.
Engineering support for new releases
Juniper supports the Junos operating system in two phases.
During engineering support of a release, the engineering teams create updated releases (maintenance and service) to address any coding issues. Juniper describes the end of engineering support as End of Engineering (EOE).
During the time of only JTAC support, the JTAC engineers help to resolve issues with solutions and workarounds that don’t require changes in the release code. Juniper describes the end of JTAC support as the End of Life (EOL).
Juniper provides a six-month notice of the EOL for each of the version releases. When the release reaches EOL, Juniper removes the software images from its site, and JTAC provides support on a reasonable commercial basis.
The last release of the year is known as an Extended End of Life (EEOL) release and provides active engineering support for three years, followed by six months of JTAC support.
Download new releases
You can find the latest supported releases of the Junos OS on Juniper’s download site.
Find the image for the particular platform that you’re upgrading. Choose between the domestic image, which is for use in the United States and Canada, and a worldwide image (export). The technical documentation for each platform is freely available in multiple formats.
Although they don’t necessarily need to, many users routinely upgrade the version of the Junos OS running on their devices. Regular upgrades ensure that they have ready access to the latest features. If their network requires a new feature, it’s already a part of the software on their devices, and they simply activate it in their deployed release whenever they’re ready to use it.
The online technical documentation, Junos Installation and Upgrade Guide, provides details about upgrading the software version of your device.
The algorithm for selecting which new version to use is straightforward: Choose a release with a higher number, and you receive the existing capabilities of your device along with the new functionality available up through to that release version. Any organization with a valid support contract can freely download new releases of the Junos OS from the Juniper support site.