A logical partition can use virtual Ethernet to establish multiple high speed inter-partition connections.
Logical partition software allows you to configure up to 16 different virtual local area networks. Virtual Ethernet provides the same function as using a 1 Gigabyte (GB) Ethernet adapter. i5/OS® and Linux partitions can communicate with each other using TCP/IP over the virtual Ethernet communication ports.
The enablement and setup of virtual Ethernet requires a restart of the Linux partition, but does not require any special hardware or software. Once a specific virtual Ethernet is enabled for a logical partition, a network device vethXX is created in the logical partition. The user can then set up TCP/IP configuration appropriately to start communicating with another partition. Virtual Ethernet provides the capability to provide multiple communication paths between applications that are run in each of the partitions.
Refer to the Linux for iSeries™ 
Web site for the latest updates to Linux running on
an iSeries.