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Figure 5 vSwitch with IP Hashing load balancing
To configure the ESXi host vSwitch for IP hash-based load balancing policy, use the following steps:
1. Configure ESXi vSwitch and vmknic port: Build a virtual switch on each ESXi host to
communicate with the NAS client network. Assign a vmknic port and two or more physical
uplink NICs to it.
2. Configure ESXi vSwitch to use Static Link Aggregation (to use the IP Hash-based load
balancing policy): The vSwitch has three load balancing options: route based on the
originating virtual port ID, Route based on IP hash, and Route based on source MAC hash. With
route based on the originating virtual port ID, the throughput cannot exceed bandwidth of one
NIC because the vmknic port of the virtual switch is bound to one specific physical NIC.
Adding more vmknic ports does not help because for a given subnet the ESX host always
chooses the first vmknic port it can find to transfer data. Similarly, in the case of MAC-based
load balancing, the vmknic port’s MAC address is associated with one physical NIC. Therefore
only one physical NIC bandwidth gets used. We recommend that the vSwitch uses the load
balancing method “Route based on IP hash” as shown in Figure 6.