Migrating continuous, 24/7 mission-critical production environments requires migration methodologies designed to prevent widespread downtime and maintain rollback capabilities.

The primary best-practice approach is parallel infrastructure deployment. By installing, cabling, and configuring the new Aruba CX core and leaf infrastructure alongside the legacy network, architects can establish temporary inter-switch links (trunks) to extend Layer 2 VLANs between the environments. This architecture allows routing protocols, overlay services, and management platforms to be validated prior to migrating live production traffic, enabling a controlled cutover.

Concurrently, at the server access edge, executing a staged migration that replaces one access switch at a time using a predefined, documented patch plan limits disruption to a small, isolated set of endpoints. Dual-homed servers and clustered systems maintain network connectivity across redundant links while individual connections are migrated. Conversely, shutting down the facility for a single cutover ( " big-bang " ) violates the customer ' s 24/7 uptime mandate, while migrating access layers before establishing core/distribution infrastructure introduces severe forwarding and spanning-tree loop risks.

Reference Topics: HPE Network Migration Strategies – Minimizing Downtime in 24/7 Environments; Parallel Core Cutover and Staged Port Migration.

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