Duplex Lan Configuration; Overview - NEC Express5800/320Fd-MR N8800-123F, EXP320K User Manual

3-24 Windows Setup and Operation

DUPLEX LAN CONFIGURATION

The NEC Express5800/ft series builds a duplex LAN configuration by using "Stratus emb-EB
2-Port Gigabit Adapter," mounted as standard on the CPU/IO module and the extended PCI slot
"NEC MT Gigabit Adapter", "NEC MF Gigabit Adapter," and "Stratus U 575 Dual Port Copper
Gigabit Adapter."

Overview

The duplex LAN configuration is of three types as described below:
Adapter Fault Tolerance (AFT)
Adapter Fault Tolerance (AFT) is a feature that places more than one LAN controller on the
same LAN (same segment), and automatically switches the process of the primary controller to
the backup controller when any trouble occurred on the primary.
Adaptive Load Balancing (ALB)
Adaptive Load Balancing (ALB) is a feature that connects more than one LAN controller to the
same hub and enhances the throughput by operating packet transmission from the server.
Receive Load Balancing (RLB) is enabled by default. Disable RLB. When RLB is enabled
the network duplex configuration may fail.
Switch Fault Tolerance (SFT)
Switch Fault Tolerance (SFT) is a feature that provides the network availability because the
fail-over target (standby) adapter takes over the MAC address/L3 address when failure occurs
on adapter/cable/connecting switch, as two adapters are connected to corresponding two
switches. One is allocated to the primary adapter and the other is allocated to the standby
adapter. On the network, the primary adapter communicates.
Regarding the path redundancy, you need to construct the environment both on the ft server
and the switch devices. Spanning Tree Protocol (SPT) function is required to construct the path
redundancy on the switch devices.
When you construct the environment, you need to set the switch priority in order to maintain
the path to the primary adapter after the path information is updated if a switch on the path is
broken. In addition, you need to set the priority to use the secondary adapter's switch if the
primary adapter's switch is broken.
The other modes, "Static Link Aggregation" and "IEEE 802.3ad Link Aggregation," do not
contribute to enhancement against a fault. When a fault occurs, the communication performed on
the controller with the fault is not taken over by the backup controller but lost.