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. In this section, we describe the networking features and functions. 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. 25GbE RoCE Express2.1 and 25GbE RoCE Express2 7.4.5 Networking features and functions 304  IBM z15 (8561) Technical Guide