Which statement accurately describes firmware upgrade behavior in an SDX environment with multiple NetScaler instances?

• A. All NetScaler instances must be upgraded simultaneously via the SDX management plane.
• B. Upgrades can only be applied if all instances run the same firmware version.
• C. Upgrades require removing instances from the SDX to upgrade them.
• D. Upgrades can be applied to individual instances, allowing different firmware versions.

Answer: (D)

In SDX, multiple NetScaler instances run as separate virtual appliances on one physical device, and you can manage their firmware independently. This means you can upgrade a single instance without touching the others, allowing different firmware versions to coexist on the same SDX. This supports staged, rolling upgrades and minimizes downtime since you can validate a new version on one instance before updating the rest. The other options don’t fit because SDX doesn’t require all instances to be upgraded at once, doesn’t require all to share the same version, and doesn’t require removing instances to perform upgrades.