Note: Load Based Teaming policy is available only with distributed virtual switch (vDS). It is not available with standard switches.
In vSphere 4.x, there are three policies:
- Route based on the originating virtual Port ID
- Route based on IP hash
- Route based on source MAC hash
These three policies provide static mapping from vSwitch port to pNIC adapter. It is possible that two heavy network load virtual machines are mapped to same physical adapter that is congested while the other adapters still have free bandwidth.
With Load Based Teaming in vSphere 4.x, after initial port based assignment, the load balancing algorithm regularly checks the load of all the teaming NICs. If one gets overloaded while another one has bandwidth available, it reassigns the port-NIC mapping to reach a balanced status. During the period until the next check is performed, the mapping is stable.
Note: Bandwidth is still limited to the maximum bandwidth a single pNIC provides.
Load Based Teaming has these advantages:
- Dynamic adjustments to load
- Different NIC speeds are taken into account. You can have a mix of 1Gbit, 10Gbit, and even 100Mbit NICs.
- To enable Load Based Teaming:
Configure the distributed virtual port group's load balancing policy to use Route based on physical NIC load.
Note: When Load Based Teaming rebalances a particular interface (vmkernel or virtual machine) to a different uplink (vmnic), it notifies the physical network switch by sending a reverse ARP. The physical switch must allow for this.