Shared Ethernet Adapter; Connecting A Virtual Ethernet To External Networks - IBM p5 590 System Handbook

A mixture of virtual Ethernet connections, real network adapters, or both are
permitted within a partition.
Virtual Ethernet can only connect partitions within a single system.
Virtual Ethernet uses the system processors for all communication functions
instead of off loading that load to processors on network adapter cards. As a
result there is an increase in system processor load generated by the use of
virtual Ethernet.

3.4 Shared Ethernet Adapter

A Shared Ethernet Adapter can be used to connect a physical Ethernet to the
virtual Ethernet. It also provides the possibility for several client partitions to
share one physical adapter.
The following sections discuss the various aspects of Shared Ethernet Adapters
such as:
Section 3.4.1, "Connecting a virtual Ethernet to external networks" on
page 73
Section 3.4.2, "Using Link Aggregation (EtherChannel) to external networks"
on page 77
Section 3.4.3, "Limitations and considerations" on page 79

3.4.1 Connecting a virtual Ethernet to external networks

There are two ways you can connect the virtual Ethernet that enables the
communication between logical partitions on the same server to an external
network.
Routing
By enabling the AIX 5L Version 5.3 routing capabilities (ipforwarding network
option) one partition with a physical Ethernet adapter connected to an external
network can act as router. Figure 3-7 shows a sample configuration. In this type
of configuration the partition that routes the traffic to the external work does not
necessarily have to be the Virtual I/O Server as in the example below. It could be
any partition with a connection to the outside world. The client partitions would
have their default route set to the partition which routes traffic to the external
network.
Chapter 3. POWER5 virtualization capabilities
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