> # Mapping pWWN to Virtual pWWN

> You can configure virtual pWWNs through real pWWNs. This process is required for NPIV hosts containing multiple pWWNs, of which only FLOGI is mapped to the virtual pWWN. Subsequent FDSIDs will have different mappings.

> Several checks are done by the NPV core to ensure the uniqueness of virtual pWWNs in the switch across the NPV switches. When duplicate virtual pWWNs are configured, the subsequent logins are rejected by the NPV core switch.

> ## Prerequisites

> - The interface must be in a shut state and the specified virtual pWWN should not be logged in.

> ## Restrictions

> - The specified virtual pWWN and the real pWWN must not be logged in.

> ## Detailed Steps

> To map pWWN to virtual pWWN, follow these steps:

> 1. In the Physical Attributes pane, expand Switches > FC Services > N_Port Virtualizer (NPV) > Flex Attach.
> 2. In the FlexAttach window, click the Physical to Virtual pWWNs tab.

> You see the Physical to Virtual pWWNs tab view.

> The LastChange field displays the time when the virtual pWWN was changed.

> Copyright 2010-2013, Cisco Systems, Inc. All rights reserved.