Enabling virtualization in a SAS expander is disclosed. For each SAS address to be virtualized through one or more physical or virtual Phy, a reference Phy associated with each SAS address is created within the expander. Next, a route table is generated that includes an entry for each of the SAS addresses being virtualized, each entry associated with one or more of the physical or virtual Phy through which the SAS address is being virtualized. With the route table so established, requests for a virtualized SAS address are routed to a particular one of the one or more physical or virtual Phy associated with the virtualized SAS address in the route table.