Chapter 4. Connectivity 115
Figure 4-7 z/OS connectivity scenario
With this environment, we will build connectivity scenarios that will include two OSA-Express
1000BASE-T features with two ports each. The ports will connect to the LAN environment
(two Cisco switches). We will also implement a HiperSockets internal LAN to interconnect all
LPARs within the same System z9. And, finally, we will use dynamic XCF connectivity,
provided by the sysplex environment, for IP traffic. The scenarios we will discuss are as
follows:
򐂰 OSA-Express connectivity
򐂰 HiperSockets connectivity
򐂰 Dynamic XCF connectivity
The other interfaces described at the beginning of this chapter are still supported and can be
used to connect to IP networks or IP hosts. However, in the following sections, we only show
how to implement what we considered to be the most commonly used interfaces.
4.3.1 OSA-Express connectivity
Configuring an OSA-Express (QDIO mode) in a single stack scenario is the simplest way to
implement your z/OS TCP/IP stack into a LAN environment. This scenario, however, still
needs to be planned to avoid any single-points of failure. Hence, we must have at least two
OSA-Express features connecting to two different switches in the network.
z/OS LPAR: A23 z/OS LPAR: A24 z/OS LPAR: A22
CHPID: F4
Devices: E800-E81F
CHPID: F5
Devices: E900-E91F
CHPID: F6
Devices: EA00-EA1F
IP Network
OSA-Express2 1000BASE-T
HiperSockets
System z9
CF38
CF LPAR:
A2E
CHPID 04
20C0-20CF
CHPID 05
20E0-20EF
CHPID 02
2080-208F
CHPID 03
20A0-20AF
Cisco
6509
Cisco
6509
116 Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 1 - Base Functions, Connectivity, and Routing
Since we are dealing with multiple LPARs in our server, for redundancy purposes we have
shared the OSA-Express ports (CHPID type OSD) across all LPARs.
In our test scenario, we have two OSA-Express 1000BASE-T features, each with two ports.
This allows us to have four CHPIDs, 02, 03, 04, and 05, shared by our three LPARs; SC30,
SC31, and SC32 (see Figure 4-7 on page 115).
To make better use of our OSA-Express ports and to control data traffic patterns, we defined
one port on each OSA-Express feature with a separate VLAN ID, creating two subnetworks to
be used by all LPARs. In a high availability configuration, these OSA-Express ports will be the
path to all of our IP addresses for the LAN environment.
Figure 4-8 OSA-Express (QDIO) implementation
Dependencies
To implement this scenario, we have the following dependencies:
򐂰 The OSA-Express port must be defined as CHPID type OSD to the server using HCD or
IOCP to enable QDIO. This CHPID must be defined as shared to all LPARs that will use
the OSA-Express port (see Example 4-1 on page 122).
򐂰 To define an OSA-Express port in QDIO mode, use the MPCIPA DEVICE statement,
specifying the PORTNAME value from the TRLE definition as the device_name. The
TRLE must be defined as MPCLEVEL=QDIO.
򐂰 The Virtual LAN identifiers (VLAN IDs) defined to each OSA-Express port must be
recognized by each switch.
򐂰 The switch ports where the OSA-Express ports are connected must be configured in trunk
mode.
z/OS LPAR: A23
Static VIPA: 10.10.1.230
z/OS LPAR: A24
Static VIPA: 10.10.1.241
z/OS LPAR: A22
Static VIPA: 10.10.1.221
IP Network
OSA-Express2 1000BASE-T
System z9
CHPID 04
20C0-20CF
CHPID 05
20E0-20EF
CHPID 02
2080-208F
CHPID 03
20A0-20AF
Cisco
6509
Cisco
6509
OSA2080 VLAN10
ipaddr: 10.10.2.232
OSA20A0 VLAN11
ipaddr: 10.10.3.233
OSA20C0 VLAN10
ipaddr: 10.10.3.234
OSA20E0 VLAN11
ipaddr: 10.10.3.235
OSA2080 VLAN10
ipaddr: 10.10.2.242
OSA20A0 VLAN11
ipaddr: 10.10.3.243
OSA20C0 VLAN10
ipaddr: 10.10.3.244
OSA20E0 VLAN11
ipaddr: 10.10.3.245
OSA2080 VLAN10
ipaddr: 10.10.2.222
OSA20A0 VLAN11
ipaddr: 10.10.3.223
OSA20C0 VLAN10
ipaddr: 10.10.3.224
OSA20E0 VLAN11
ipaddr: 10.10.3.225

Get Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 1: Base Functions, Connectivity, and Routing now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.