The capabilities of the WWPN are extended to calculate and show WWPNs for virtual and physical ports ahead of system installation. 

The tool assigns WWPNs to each virtual FCP channel or port by using the same WWPN assignment algorithms that a system uses when assigning WWPNs for channels that use NPIV. Therefore, the SAN can be set up in advance, which allows operations to proceed much faster after the server is installed. In addition, the SAN configuration can be retained instead of altered by assigning the WWPN to physical FCP ports when a FICON feature is replaced. 

The WWPN tool takes a . csv  file that contains the FCP-specific I/O device definitions and creates the WWPN assignments that are required to set up the SAN. A binary configuration file that can be imported later by the system is also created. The . csv  file can be created manually or exported from the HCD/HCM. The supported operating systems are listed in Table 7-6 on page 264 and Table 7-7 on page 266. 

The WWPN tool is applicable to all FICON channels that are defined as CHPID type FCP (for communication with SCSI devices) on z15. It is available for download at the Resource Link at the following website (log in is required). 

Note: An optional feature can be ordered for WWPN persistency before shipment to keep the same I/O serial number on the new CPC. Current information must be provided during the ordering process. 

## 7.4.5 Networking features and functions 

In this section, we describe the networking features and functions. 

## 25GbE RoCE Express2.1 and 25GbE RoCE Express2 

Based on the RoCE Express2 generation hardware, the 25GbE RoCE Express2 (FC 0430 and 0450) provides two 25GbE physical ports and requires 25GbE optics and Ethernet switch 25GbE support. The switch port must support 25GbE (negotiation down to 10GbE is not supported). 

The 25GbE RoCE Express2 has one PCHID and the same virtualization characteristics and the 10GbE RoCE Express2 (FC 0412 and FC 0432); that is, 126 Virtual Functions per PCHID. 

z/OS requires fixes for APAR OA55686. RMF 2.2 and later is also enhanced to recognize the CX4 card type and properly display CX4 cards in the PCIe Activity reports. 

25GbE RoCE Express2 feature also are used by Linux on Z for applications that are coded to the native RoCE verb interface or use Ethernet (such as TCP/IP). This native exploitation does not require a peer OSA. 

Support for select Linux on Z distributions is now provided for Shared Memory Communications over Remote Direct Memory Access (SMC-R) by using RoCE Express features. For more information, see this Linux on Z Blogspot web page. 

The supported operating systems are listed in Table 7-8 on page 267 and Table 7-9 on page 269. 

