Link aggregation for specific VxRail networks is supported starting with VxRail version 7.0.130. NIC teaming in VxRail is the foundation for supporting link aggregation, which is the bundling of two physical network links to form a single logical channel. Link aggregation allows ports on a VxRail node to peer with a matching pair of ports on the top-of-rack switches to support load balancing and optimize network traffic distribution across the physical ports. VxRail networks with heavy resource requirements, such as vSAN and potentially vMotion, benefit most from network traffic optimization.
Each VxRail network is assigned two uplinks by default during the initial implementation operation. One uplink is designated as ‘active’, and the other uplink as ‘standby’. Under this model, resource-intensive networks are limited to the bandwidth of a single uplink. Enabling link aggregation allows the VxRail network to use the bandwidth of both uplinks, with the traffic flow coordinated based on the load-balancing hash algorithm.
The following guidelines must be followed when using NIC teaming and link aggregation with VxRail:
Support for LACP, the selection of load-balancing hashing algorithms and the formation of link aggregation on the physical switches depends on the switch vendor and operating system. These features are usually branded by the vendor, using names such as ‘Ether-Channel’, ‘Ethernet trunk’, or ‘Multi-Link Trunking’. Consult your switch vendor to verify that the switch models planned for the VxRail cluster supports this feature.
If you plan to deploy a pair of switches to support the VxRail cluster, and you want to enable load balancing across both switches, you must configure multi-chassis link aggregation. This feature is usually branded by the switch vendor, such as Cisco’s Virtual Port Channel or Dell’s VLT Port Channel. See the guides provided by your switch vendor for the steps to complete this task.
Enabling load balancing for the non-management VxRail networks requires peering the pair of ports on each VxRail node with a pair of ports on the top-of-rack switches.
If you are enabling link aggregation across a pair of switches, and you have matching open ports on both switches, the best practice is to plug the cables into equivalent port numbers on both switches. We recommend creating a table to map each VxRail node port to a corresponding switch port. Then, identify which ports on each VxRail will be enabled for link aggregation.
For example, if you want to deploy a VxRail cluster with four nodes, and reserve and use two ports on the NDC and two ports on a PCIe adapter card for the VxRail cluster, and use the first eight ports on a pair of top-of-rack switches for connecting the cables, you could use the resulting table to identify the switch ports to be configured for link aggregation.
Assuming that you are using the second port on the NDC and PCIe adapter card for the non-management VxRail networks, you can identify the switch port pairs, as shown in the columns shaded green, to be configured for link aggregation.
Dell Technologies recommends creating a table mapping the VxRail ports to the switch ports and part of the planning and design phase.