> # WWN Assignment for iSCSI Initiators

> An iSCSI host is mapped to an N port’s WWNs by one of the following mechanisms:

> - Dynamic mapping (default)
> - Static mapping

> ### Dynamic Mapping

> With dynamic mapping, an iSCSI host is mapped to a dynamically generated port WWN (pWWN) and node WWN (nWWN). Each time the iSCSI host connects it might be mapped to a different WWN. Use this option if no access control is required on the Fibre Channel target device (because the target device access control is usually configured using the host WWN).

> The WWNs are allocated from the MDS switch's WWN pool. The WWN mapping to the iSCSI host is maintained as long as the iSCSI host has at least one iSCSI session to the IPS port. When all iSCSI sessions from the host are terminated and the IPS module or MPS-14/2 module performs an FLOGO for the virtual N port of the host, the WWNs are released back to the switch's Fibre Channel WWN pool. These addresses are then available for assignment to other iSCSI hosts requiring access to the Fibre Channel Fabric.

> The following are three dynamic initiator modes are supported:

> - iSCSI—Dynamic initiators are treated as iSCSI initiators and can access dynamic virtual targets and configured iSCSI virtual targets.
> - iSLB—Dynamic initiators are treated as iSLB initiators.
> - Deny—Dynamic initiators are not allowed to log in to the MDS switch.

> iSCSI dynamic mapping is the default mode of operation. This configuration is distributed using CFS.

> Note Configuring dynamic initiator modes is supported only through the CLI, not through Device Manager or Cisco DCNM for SAN.

> Copyright 2010-2015, Cisco Systems, Inc. All rights reserved.