What concept can reduce the number of ports required for ISLs?

Zoning controls access and connectivity within a SAN fabric, but it does not reduce the number of physical ports required for ISLs.

Locality refers to the physical proximity or logical grouping of resources and does not directly relate to reducing the number of ports for ISLs.

Trunking, or port channeling, combines multiple physical Fibre Channel ISLs between two switches into a single logical ISL. This aggregation provides increased bandwidth and resilience, effectively reducing the number of individually managed ISL ports.

Routing in a SAN context involves directing traffic between different fabrics or zones, but it does not inherently reduce the number of physical ports needed for ISLs within a single fabric.