> # Interface Modes

> Each physical Fibre Channel interface in a switch may operate in one of several port modes: E port, F port, FL port, TL port, TE port, SD port, ST port, and B port . Besides these modes, each interface may be configured in auto or Fx port modes. These two modes determine the port type during interface initialization.

> Note Interfaces are created in VSAN 1 by default. See the Cisco MDS 9000 Family NX-OS Fabric Configuration Guide.

> Each interface has an associated administrative configuration and an operational status:

> - The administrative configuration does not change unless you modify it. This configuration has various attributes that you can configure in administrative mode.
> - The operational status represents the current status of a specified attribute like the interface speed. This status cannot be changed and is read-only. Some values may not be valid when the interface is down (for example, the operational speed).

> Note When a module is removed and replaced with the same type of module, the configuration is retained. If a different type of module is inserted, then the original configuration is no longer retained.

> Each interface is briefly described in the sections that follow.

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