A VxRail cluster depends on adjacent switches, usually a Top-of-Rack (ToR) switch, as it enables all connectivity between VxRail nodes since they have no backplane. The VxRail nodes can attach to any compatible network infrastructure at 1/10/25 GbE speeds using RJ45 or SFP+ ports. Most production environments deploy dual ToR switches to avoid having a single point of failure. Typically, all network traffic configured in a VxRail traffic is Layer 2 (data link layer), where all hosts are on the same broadcast domain and do not require routing services. A Layer 2 configuration makes it easier to administer and integrate with the upstream network. Additionally, one or more switches do not have to support Layer 3 (network layer) services that require routing beyond the local broadcast domain (which requires more configuration and management). Choose a switch that has IPv6 multicast functionality, as VxRail nodes use this for the node discovery process. In a production environment, deploying managed switches is recommended.
Consider switch performance when selecting the best ToR switch solution:
- When deploying all-flash storage on the VxRail cluster, the minimum supported switch speed is 10 GbE. Dell Technologies recommends using switches with 25 GbE speeds if possible.
- When planning to use advanced features on the switch, such as Layer 3 routing services, choose a switch with sufficient resources to accommodate for switch buffer space contention.
- Switches with higher port speeds are designed with higher Network Processor Unit (NPU) buffers. An NPU shared switch buffer of at least 16 MB is recommended for 10 GbE network connectivity, and an NPU buffer of at least 32 MB is recommended for 25 GbE network connectivity.
- For large VxRail clusters with demanding performance requirements and advanced switch services enabled, choose switches with additional resource capacity and deeper buffer capacity.