A stateful network appliance used for city VPN aggregation cannot easily run two versions side by side. Which deployment strategy is most realistic for its upgrade?
Select an answer to reveal the explanation.
Short Explanation
Some boxes are stubborn — one appliance, lots of state, no twin that can take half the tunnels cleanly. That is when you carefully upgrade the same box in a window. Parallel blue-green or canary slices need workable dual paths that this stateful gear may not offer.
Full Explanation
In-place deployment is often required when parallel environments are impractical — for example, stateful appliances that cannot split sessions cleanly across two versions. Controlled downtime and careful backup/rollback planning replace dual-stack strategies. Blue-green, canary, and multi-node rolling assume alternate capacity or multiple peers that this scenario lacks.