What you will learn
A comprehensive Cisco NX-OS Software release methodology has been developed that both preserves the integrity and stability of mission-critical networks and has the flexibility to respond to market needs for timely delivery of advanced networking features with multilayer intelligence.
This document is a guide to understanding the Cisco NX-OS Software release methodology. It describes the types of releases, their functions, and their lifecycles with various scenarios. It also describes the Cisco NX-OS Software release and image naming conventions. Throughout this document Cisco Nexus® 9000 is used as a reference platform for simplicity. However, this policy is applicable to all NX-OS platforms.
Types of Cisco NX-OS Software releases
Table 1 lists the Cisco NX-OS Software release variants: major+, major releases or trains, and minor/maintenance releases.
Table 1. Cisco NX-OS Software release types
Cisco NX-OS Software release type
A major+ release is considered a superset train, which carries all attributes of a major release but can have further additional key changes (for example, 64-bit kernel) or other significance that requires bumping up of the release numbering.
Example: Release 9.
A major release or software train introduces significant new features, functions, and/or hardware platforms. Each major release consists of multiple major releases and is its own train. Each minor release enhances a major release.
Examples: Releases 9.2(*), Release 9.3(*), etc.
As shown in Figures 2 and 3, a release train will have the first couple of releases with minor feature-sets, enhancements, bug fixes, and posts that will transition to a maintenance release, primarily resolving product defects in a maintenance release. Helping ensure that each maintenance release addresses product defects preserves the integrity and stability of the minor release.
Examples: Releases 9.2(2) and 9.2(3).
Each Cisco NX-OS Software release is uniquely numbered as X.Y(z), where X is the major+ release or train, Y is a major train feature release that enhances major+ release X, and z is a minor/maintenance release that addresses product defects in major release Y.
Figure 1 is a graphical representation of the Cisco NX-OS Software releases, based on the example of the Cisco Nexus 9000 Series Switches.
Figure 1. Cisco NX-OS Software releases on Cisco Nexus 9000 Series Switches
Patch release identifier 9.2(2a) in the above example is reserved for extremely rare cases, to address a software field alert or security deferral or advisory.
An example of a previous release number is: 7.0(3)I7(6). In this format, the “I” is the platform designator.
Long-lived and short-lived releases
Each Cisco NX-OS major+ release or train has at least one long-lived release and one or more short-lived releases.
● Long-lived releases: Software releases that have been undergoing frequent maintenance to help ensure quality and stability are called long-lived releases. Each major+ release generally has at least one long-lived release, which will be maintained for a longer time span than other releases. Long-lived releases are recommended for the deployment of widely adopted functions or for networks that will not be upgraded frequently.
● Short-lived releases: Software releases that introduce new hardware or software innovations are typically short-lived releases. Each major+ release generally has at least one short-lived release, which are characterized by occasional maintenance releases, as needed. Short-lived releases are recommended for deployment if the adoption of new hardware or of software innovations is of interest. As a best practice, short-lived software releases should be upgraded to the next available long-lived release for stability and longer maintenance benefits.
Lifecycle of a Cisco NX-OS Software release
The lifecycle of a major release spans several minor and maintenance releases. Figure 2 illustrates the lifecycle of a long-lived release.
Figure 2. Lifecycle of a long-lived software release
The lifecycle of a major long-lived release starts with the First Customer Shipment (FCS) of the first minor release. It represents the date of the first shipment of a software release to customers for revenue.
The major release then enters the next phase, in which several releases are made available to address product defects as well as bring additional features to the branch of NX-OS.
After the code integrity and stability is established, the long-lived release achieves maturity and broad adoption. At this stage, the major release has been proven with extensive market exposure in diverse deployment scenarios and has passed rigorous metrics analyzing quality, stability, and problem trends. Afterward, the major release transitions to the mature maintenance phase. In this phase, the release receives defect repairs only for severity 1 and severity 2 defects that the customer finds. Problems found internally are addressed on a case-by-case basis.
Subsequently, it enters the final phase, under which is receives only Product Security Incident Response Team (PSIRT) fixes and then enters end of life. Official end-of-life announcements generally lag, and this document should be used for software-release-cycle planning for getting up to date PSIRT fixes. As noted in the software-release cycle, post 36 months (in case of Long Lived release) a train stops taking PSIRT fixes too, and expectation is for next long lived release to pick up the new PSIRT updates. Critical PSIRT fixes are made available only in the latest Long Lived release train, regardless of whether previous Long-Lived release End-of-Life announcements are made or not.
Cisco will generally provide a six-month notice of a product's end-of-sale date or the last day when the affected product can be ordered. The software release will still be available through Cisco.com and remain fully supported by Cisco.
Figure 3 illustrates the lifecycle of a short-lived release, which is characterized by similar, but shorter, phases as the long-lived release.
Figure 3. Lifecycle of a short-lived software
After First Customer Shipment (FCS) of each short-lived release, there is an initial deployment phase in which product defects are addressed in maintenance releases.
To preserve the integrity, stability, and quality of a minor release, one or two releases will be provided primarily to address product defects and include new features or functions.
Subsequent maintenance releases will be provided on an as-needed basis.
Short-lived releases reach their end-of-sale milestone in 12 to 18 months after FCS, which represents the last date that the product can be ordered through Cisco customer service or manufacturing. Cisco will generally provide a six-month notice of a product's end-of-sale date or the last day when the affected product can be ordered. For short-lived releases, PSIRT fixes will be performed during the initial lifecycle up until MR1/2. After that, it is recommended to move to the next release to incorporate PSIRT fixes. The software release will still be available through Cisco.com and remain fully supported by Cisco.
After the end-of-sale milestone, a release achieves end-of-software maintenance status, which represents the last potential date for maintenance software to be released. Engineering will no longer actively apply any defect repairs to the release. Software defects are addressed by upgrading to a subsequent release. The product will still be available through Cisco field support offices and Cisco.com.
Finally, the release reaches end-of-life status, in which the software image is no longer supported by Cisco and is removed from Cisco.com.
Cisco NX-OS cadence-based software-release methodology preserves the integrity, stability, and quality of customers' mission-critical networks. It has the flexibility to respond to market needs for timely delivery of innovative features. Primary attributes of release methodology include the following:
● Major releases introduce significant new features, functions, and platforms
● Minor releases enhance the features and functions of an existing major release
● Maintenance releases address product defects in a minor release
For more information:
● Cisco Nexus 9000 Series Switches release notes: https://www.cisco.com/c/en/us/support/switches/nexus-9000-series-switches/products-release-notes-list.html.
● Cisco Nexus 9000 Series Switches minimum recommended Cisco NX-OS releases: https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/recommended_release/b_Minimum_and_Recommended_Cisco_NX-OS_Releases_for_Cisco_Nexus_9000_Series_Switches.html.
● Cisco Nexus 9000 End of Life, End of Sales Notices: https://www.cisco.com/c/en/us/products/switches/nexus-9000-series-switches/eos-eol-notice-listing.html.