Junos OS Release Numbers

The release number represents a particular revision of the software that runs on a Juniper Networks routing platform, for example, Junos OS Release 14.1,14.2, 15.1, or 17.1. Each release has certain new features that complement the software processes that support Internet routing protocols, control the device’s interfaces and the device chassis itself, and allow device system management. On the Juniper Networks Support web page, you download software for a particular release number. In this example, we dissect the format of the software release number to show what it indicates. The generalized format is as follows: Given the format of m.nZb.s The software release number 17.2R1.13, for example, maps to this format as follows: m is the main release number of the product, for example, 17. n is the minor release number of the product, for example, 2. Z is the type of software release, for example, R for FRS or maintenance release. For types of software releases, see Table 4. b is the build number of the product, for example, 1, indicating the FRS rather than a maintenance release.. s is the spin number of the product, for example, 13. Table 4: Software Release Types Release Type Description R First revenue ship (FRS) or maintenance release software. R1 is FRS. R2 onward are maintenance releases. F Feature velocity release. Feature velocity releases are only in Junos OS Release 15.1. B Beta release software. I Internal release software. These are private software releases for verifying fixes. S Service release software, which are released to customers to solve a specific problem—this release will be maintained along with the life span of the underlying release. The service release number is added after the R number, for example, 14.2R3-S4.4. Here S4 represents the 4th service release on top of 14.2R3 and is the 4th re-spin. X Special (eXception) release software. X releases follow a numbering system that differs from the standard release numbering. Starting with Junos OS Release 12.1X44-D10, SRX Series Firewalls follow a special naming convention for Junos OS releases. For more information, refer to the Knowledge Base article KB30092 at https://kb.juniper.net/InfoCenter/index?page=home. Note: Prior to Junos OS Release 11.4, the software release number format for service releases was same as other releases. For example, 10.4S4.2 represented the 4th service release and 2nd re-spin of 10.4.