ACME Inc., in partnership with Cisco, has evaluated the requirements for their deployment based on the software features required, the support for the hardware platforms they have selected, and the maturity of the software releases. They have selected a target version of software for their deployment. Additionally, they have put a proactive plan in place to revisit this decision periodically to determine if future upgrades are required.
The software versions for Cisco Application Centric Infrastructure (ACI) are listed in the following format:
major—Represents major changes in the product architecture, platform, or features content.
minor—Represents a minor release with new software features.
maintenance—Represents bug fixes to a feature release of Application Policy Infrastructure Controller (APIC). This changes when there are fixes for product defects in the software, but no additional new features.
The following example shows some APIC versions:
1.0(1e) 1.1(1j) 1.2(1i)
Both the software for the APIC and the fabric nodes are denoted by the same version scheme. For example, the APIC 1.2(1i) release corresponds to the switch software 11.2(1i) release. The release notes for the APIC versions reference the corresponding switch versions, and vice versa.
All components of the ACI infrastructure including the APIC, leaf switches, and spine switches, should be on the same version. While at the time of upgrading, disparate versions may exist between APIC and the switches, do not operate the fabric for extended periods of time in this state.
When considering the impact and risk of upgrading, you can assume that a maintenance version upgrade, such as upgrading from 1.1(1j) to 1.1(1o), will have less impact than a major/minor version upgrade, as there will be only bug fixes and no new features added.
There are three main components that can be upgraded:
- Switches (leaf and spine)
- Application Policy Infrastructure Controller (APIC)
- Catalog firmware
Firmware group policies on the Application Policy Infrastructure Controller (APIC) define the group of nodes on which firmware will be upgraded. For most deployments, a single firmware group is adequate.
Maintenance group policies define a group of switches that will be jointly upgraded to the associated firmware set. Maintenance groups can be upgraded on demand or according to a schedule, making it possible to defer an upgrade task to a business maintenance window. Typically, there are two maintenance groups, each containing a set of leafs and spines. Each maintenance group is upgraded separately.
The APIC firmware policy applies to all controllers in the cluster, but the upgrade is always done sequentially. The APIC GUI provides real-time status information about firmware upgrades. Controller firmware policies can be upgraded on demand or according to a schedule.
Each firmware image includes a compatibility catalog that identifies supported switch models. The APIC maintains a catalog of the firmware images, switch types, and models that are allowed to use that firmware image. The APIC, which performs image management, has an image repository for compatibility catalogs, APIC firmware images, and switch images.