6947axA.fm Draft Document for Review April 7, 2004 6:15 pm
236 IBM eServer zSeries 990 Technical Guide

Notes on wiring with multiple adapters:

򐂰It is intended that a Hardware Management Console and the SE together be connected by
only one LAN.
򐂰Multiple adapters in a Hardware Management Console allow that Hardware Management
Console to connect with two independent sets of SEs: one set on a token ring and a
second set on an Ethernet.
This is done to allow for migration from token ring environments to Ethernet environments.
򐂰Multiple adapters in a ThinkPad® SE are intended to allow two different Hardware
Management Consoles to have independent paths to the SE.
This is done so that the console can be controlled if one LAN goes down.
In the following sections, we describe the four wiring scenarios.
Token ring only wiring scenario
The token ring only wiring scenario, shown in FigureA-4, is the standard wiring approach
used in previous generations of the IBM Enterprise Server Hardware Management Console
and Support Element wiring. As in previous systems, each system includes a Multistation
Access Unit (MAU) that may be used to interconnect the token ring adapter wiring of the
Support Elements to the Hardware Management Console. Token ring wiring may be used to
interconnect the MAUs to form a larger private LAN where multiple systems are to be
controlled by a single Hardware Management Console.
Figure A-3 Token ring only wiring scenario
Important: The z890 and z990 will be the last zSeries servers to offer Token Ring adapter
features on the Hardware Management Consoles (HMCs), Support Element (SEs), and
Trusted Key Entry (TKE) workstations. The IBM 2074 Model 3 Console Support Controller
will be the last controller to offer Token Ring adapter features.
IBM zSeries is making these statements to allow enterprises sufficient opportunity to
prepare for a migration to Ethernet environments.
z990
Primary
SE
Alternate
SE

Token-Ring LAN

Token-Ring LAN