Host Ethernet Adapter Device Driver

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The Host Ethernet Adapter Device Driver supports the following additional configuration parameters:

Enable Alternate Ethernet Address (use_alt_addr): Specifies whether the adapter uses the MAC address that is specified in the Alternate Ethernet Address attribute. You can set the attribute value to Yes or No. The default value is No.
Enable RX and TX Checksum Offload of TCP Segments (tx_cksum and rx_cksum): Specifies whether the adapter is to perform receive checksum calculation and transmit checksum calculation for TCP segments. You can set the attribute value to Yes or No. The default value is Yes.
Flow Control (flow_ctrl): Specifies whether the adapter enables transmit flow control and receive flow control. You can set the attribute value to Yes or No. The default value is Yes. The setting is only applicable to a system that is not managed by Hardware Management Console (HMC) or by Integrated Virtualization Manager (IVM).
Jumbo Frames (jumbo_frames): Specifies whether to transmit and receive jumbo frames, which range from 1522 bytes through 9022 bytes in size. You can set the attribute value to Yes or No. The default value is No. To enable the attribute, authorization from HMC or IVM is required. Disablement of this attribute is not dependent on HMC or IVM.
Receive Processing Count (rx_proc): Indicates the number of receive descriptor that is processed before posting a work-queue element. The default value is determined per performance tuning.
Enable TX TCP Resegmentation Offload of TCP Segments (large_send): Specifies whether the adapter is to perform transmit TCP resegmentation for TCP segments. You can set the attribute value to Yes or No. The default value is Yes.
Transmit Immediate Data Copy Threshold (tx_immd_copy): Specifies the maximum size for copying data into the immediate data area inside the transmit work-queue element. This value is tunable for performance. Possible values range from 136 through 224. The default value is 224.
Requested Media Speed (media speed): Indicates the speed at which the adapter attempts to operate. The available speeds are 10 Mbps full-duplex, 100 Mbps full-duplex, 1000 Mbps full-duplex, 10 000 Mbps full-duplex, and autonegotiation. The default is autonegotiation. Select autonegotiate when the adapter must use autonegotiation across the network to determine the speed. When the network does not support autonegotiation, select a specific speed.
Note: Half-duplex is not a valid value. This attribute is only applicable to a system that is not managed by HMC or by IVM.
Enable Multicore Scaling (Multicore): Enables or disables driver multithreading. You can set the attribute value to Yes or No. The default value is Yes. The multithreading value is specified by the HMC MCS parameter.
Use Transmit Interface Specific Buffers (tx_isb): Enables or disables transmit copy optimizations. You can set the attribute value to Yes or No. The default value is Yes.
Enable Receive TCP Segment Aggregation (large_receive): Enables coalescing receive packets into a larger packet before passing to the upper layer for enhanced performance. You can set the attribute value to Yes or No. The default value is No.
Note: Disable this value when the adapter is used in IP forwarding.
Receive Packet Coalescing (rx_coalesce): Allows tuning of the RX packets that are coalesced before passing to a stack. Increasing this value impacts latency under certain scenarios. Decreasing this value might enhance large reception under limited scenarios. You can set the attribute to a value ranging from 1 through 64. The default value is 16, which demonstrates the best balance of performance versus latency.