Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 1: Base Functions, Connectivity, and Routing

112 Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 1 - Base Functions, Connectivity, and Routing

Figure 4-5 HiperSockets Accelerator

For more information about HiperSockets, refer to zSeries HiperSockets, SG24-6816.

4.2.3 Dynamic XCF

From an IP topology perspective, DYNAMICXCF establishes fully meshed IP connectivity to

all other z/OS TCP/IP stacks in the Sysplex. We only need one end-point specification in

each stack for fully meshed connectivity to all other stacks in the Sysplex. When a new stack

gets started, Dynamic XCF connectivity is automatically established.

Dynamic XCF is required to support Sysplex Distributor and nondisruptive dynamic VIPA

movement (discussed in detail in Communications Server for z/OS V1R7 TCP/IP

Implementation, Volume 3 - High Availability, Scalability, and Performance, SG24-7171).

Dynamic XCF uses Sysplex Sockets support, allowing the stacks to communicate with each

other and exchange information such as VTAM CPNAMEs, MVS SYSCLONE value, and IP

addresses. The dynamic XCF definition is activated by coding the IPCONFIG DYNAMICXCF

parameter in the TCP/IP profile.

Dynamic XCF creates definitions for DEVICE, LINK, HOME, and BSDROUTINGPARMS

statements and the START statement dynamically. When activated, the dynamic XCF

devices and links appear to the stack as though they had been defined in the TCP/IP profile.

They can be displayed using standard commands, and they can be stopped and started.

LPAR A LPAR B LPAR C LPAR D

System z9 or zSeries Server

TCP/IP

Stack A

TCP/IP

Stack B

TCP/IP

Stack C

TCP/IP

Stack D

HiperSockets

(CHPID FE)

HiperSockets

(CHPID FD)

LPAR E

OSA-E

Gigabit Ethernet Network

OSA-E

Note: This example is intended purely to demonstrate IP traffic flow. We do not

recommend implementing HiperSockets Accelerator using a single LPAR.

Note: Only one dynamic XCF network is supported per Sysplex.