Hmc Connectivity To The Power7+ Processor-Based Systems - IBM Power 720 Overview

2.11.1 HMC connectivity to the POWER7+ processor-based systems

POWER7+ processor technology-based servers and their predecessor systems that are
managed by an HMC require Ethernet connectivity between the HMC and the server's
service processor. In addition, if dynamic LPAR, Live Partition Mobility, or PowerVM Active
Memory Sharing operations are required on the managed partitions, Ethernet connectivity is
needed between these partitions and the HMC. A minimum of two Ethernet ports are needed
on the HMC to provide such connectivity.
For any logical partition in a server it is possible to use a Shared Ethernet Adapter that is
configured through a Virtual I/O Server. Therefore, a partition does not require its own
physical adapter to communicate with an HMC.
For the HMC to communicate properly with the managed server, eth0 of the HMC must be
connected to either the HMC1 or HMC2 ports of the managed server, although other network
configurations are possible. You can attach a second HMC to HMC2 port of the server for
redundancy. These must be addressed by two separate subnets. Figure 2-36 shows a simple
network configuration to enable the connection from the HMC to the server and to enable
dynamic LPAR operations. For more details about HMC and the possible network
connections, see Power Systems HMC Implementation and Usage Guide, SG24-7491
(previous edition was named Hardware Management Console V7 Handbook, SG24-7491).
Figure 2-36 HMC to service processor and LPARs network connection
The default mechanism for allocation of the IP addresses for the service processor HMC
ports is dynamic. The HMC can be configured as a DHCP server, providing the IP address at
the time that the managed server is powered on. In this case, the FSPs are allocated an IP
address from a set of address ranges that are predefined in the HMC software. These
predefined ranges are identical for version V7R7.1.0 of the HMC code and for previous
versions.
If the service processor of the managed server does not receive a DHCP reply before time
out, predefined IP addresses will be set up on both ports. Static IP address allocation is also
an option. You can configure the IP address of the service processor ports with a static IP
address by using the Advanced System Management Interface (ASMI) menus.
eth1
eth0
HMC
Management LAN
entx
LPAR
HMC1 1
Service
Processor
HMC2
Power Systems server
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