Layer23 is not supported on Gen1 (24x1, 20x1, 4x10) and Darter (24x10) cards.
However, Gen1 should support Layer3.
This is due to current XPP limitation.
Currently, there is no plan to support Layer23 on Gen1 cards.
Note: all Gen2 (20x10, 2x100, 8x10, 4x40) except for Darter (24x10) support Layer23 flows
For clarification on Gen1, Gen2, Gen3 module support please refer to the Module Compatibility Matrix in release notes up to NI 5.9.00x versions and the Supported Modules table in release notes NI 6.0.00 and later.