Azure Virtual Network Peering, as it allows for connecting multiple virtual networks across different regions without the need for additional gateways, ensuring global connectivity.

Azure Virtual Subnets, which enable the creation of isolated network segments within a single virtual network, providing department-specific isolation without the complexity of managing multiple virtual networks.

Azure VPN Gateway, offering secure connectivity between on-premises networks and Azure, suitable for hybrid cloud scenarios but not specifically for subnet isolation within Azure.

Azure ExpressRoute, providing dedicated private network connectivity for high-throughput and low-latency requirements, but not designed for subnet isolation within a virtual network.