The supported operating systems are listed in Table 7-8 on page 255 and Table 7-9 on page 257. 

## HiperSockets Multiple Write Facility 

The HiperSockets Multiple Write Facility allows the streaming of bulk data over a HiperSockets link between two LPARs. Multiple output buffers are supported on a single Signal Adapter (SIGA) write instruction. The key advantage of this enhancement is that it allows the receiving LPAR to process a much larger amount of data per I/O interrupt. This process is transparent to the operating system in the receiving partition. HiperSockets Multiple Write Facility with fewer I/O interrupts is designed to reduce processor utilization of the sending and receiving partitions. 

Support for this function is required by the sending operating system. For more information, see “HiperSockets” on page 183. The supported operating systems are listed in Table 7-8 on page 255. 

## HiperSockets support of IPV6 

IPv6 is expected to be a key element in the future of networking. The IPv6 support for HiperSockets allows compatible implementations between external networks and internal HiperSockets networks. The supported operating systems are listed in Table 7-8 on page 255 and Table 7-9 on page 257. 

## HiperSockets Layer 2 support 

For flexible and efficient data transfer for IP and non-IP workloads, the HiperSockets internal networks on z14 can support two transport modes: Layer 2 (Link Layer) and the current Layer 3 (Network or IP Layer). Traffic can be Internet Protocol (IP) Version 4 or Version 6 (IPv4, IPv6) or non-IP (AppleTalk, DECnet, IPX, NetBIOS, or SNA). 

HiperSockets devices are protocol-independent and Layer 3-independent. Each HiperSockets device features its own Layer 2 Media Access Control (MAC) address. This MAC address allows the use of applications that depend on the existence of Layer 2 addresses, such as Dynamic Host Configuration Protocol (DHCP) servers and firewalls. 

Layer 2 support can help facilitate server consolidation. Complexity can be reduced, network configuration is simplified and intuitive, and LAN administrators can configure and maintain the mainframe environment the same way as they do a non-mainframe environment. 

The supported operating systems are listed in Table 7-8 on page 255 and Table 7-9 on page 257. 

## HiperSockets network traffic analyzer for Linux on Z 

Introduced with IBM System z10, HiperSockets network traffic analyzer (HS NTA) provides support for tracing Layer2 and Layer3 HiperSockets network traffic in Linux on Z. This support allows Linux on Z to control the trace for the internal virtual LAN to capture the records into host memory and storage (file systems). 

Linux on Z tools can be used to format, edit, and process the trace records for analysis by system programmers and network administrators. 

## OSA-Express7S 25 Gigabit Ethernet SR 

OSA-Express7S 25GbE (FC 0429) is installed in the PCIe I/O drawer and has one 25GbE physical port and requires 25GbE optics and Ethernet switch 25GbE support (negotiation down to 10GbE is not supported). 

