What Does Shared Ethernet Adapter Mean?
A shared Ethernet adapter is a virtual input/output (I/O) server component that connects a physical Ethernet adapter to one or more virtual Ethernet adapters. If shared Ethernet adapters are on a virtual I/O server's logical partition, Ethernet adapters on client logical partitions will be able to access data beyond network traffic. Shared Ethernet adapters also facilitate easy communication with stand-alone servers and logical partitions on other systems, eliminating the need for an external network.
Techopedia Explains Shared Ethernet Adapter
A shared Ethernet adapter connects the internal virtual local area networks (VLANs) to external switches. This bridge enables logical partitions to share the IP subnet with stand-alone servers and other external logical partitions. The shared Ethernet adapter sends the outbound packets received from a virtual Ethernet adapter to the external network, while the inbound packets go to a particular client's logical partition through a virtual Ethernet link. A packet's original media access control address and VLAN tags are visible to other computers on the physical network because the packets are processed at the second layer.
Few types of packets are tagged as high-priority packets by the quality of service (QoS), a bandwidth apportioning feature on shared Ethernet adapters. The priority value and relative importance for VLAN traffic are represented by numbers ranging from zero to seven, where No.1 represents the most important packet, zero represents the default value and No.7 represents the least important packet.
The virtual I/O administrator can use QoS by selecting shared Ethernet adapter qos_mode, which offers three different attributes: disabled, strict and loose modes.