The second and third vDS provide several different network topologies. Some of these topologies are covered in this section. Note in these examples, we focus on the connectivity from the vDS and do not take the NIC card to vDS uplink into consideration. With the new features for custom and advanced NIC profiles, there are too many combinations to cover in this guide.

Two vDS (system and NSX) – 4‑pNIC topology

The first option uses four pNICs, two uplinks on the VxRail (system) vDS, and two uplinks on the NSX vDS.

Figure 17.    Two vDS with four pNICs

If we now consider the two-vDS design and NIC-level redundancy, the VxRail vDS must be deployed using a custom profile using uplink1/uplink2 for all traffic. Uplink 1 must be mapped to a port on the NDC and the second uplink2 must be mapped to a port on the PCIe, providing NIC-level redundancy for the system traffic. When the VxRail cluster is added to VCF, the remaining two pNICs (one from NDC and one from PCIe) can be selected to provide NIC-level redundancy for the NSX traffic. The next figure illustrates this network design.

Note: Both ports from NDC must connect to switch A, and both ports from the PCIe must connect to switch B. These connections are required for VCF VMNIC lexicographic ordering.

Figure 18.    Two vDS with custom profile and NIC-level redundancy

Two vDS (system and NSX) – 6‑pNIC topologies

There are two options in a 6-pNIC design with two vDS. For the first option, we have four pNICs on the VxRail vDS and use two additional pNICs dedicated for NSX traffic on the NSX vDS. This option might be required to keep Mgmt and vSAN/vMotion on different physical interfaces and also if NSX needs its own dedicated interfaces.

Figure 19.    Two vDS with six pNICs option 1

The second option with six pNICs uses a system vDS with two pNICs and the NSX vDS with four pNICs. This configuration increases the bandwidth for NSX east-west traffic between transport nodes. The use case for this design might be when the east-west bandwidth requirement scales beyond two pNICs. The host overlay traffic uses all four uplinks on the NSX vDS, load-balanced using source ID teaming. By default, the Edge VMs, including the Edge overlay and Edge uplink traffic, use uplink 1 and 2 on NSX vDS.

Note: Starting with VCF 4.3, you can select which uplinks to use on the vDS for the Edge VM traffic when a dedicated NSX vDS has been deployed with four uplinks.

Figure 20.    Two vDS with six pNICs option 2

Two vDS (system and NSX) – 8‑pNIC topologies

The 8-pNIC option that is illustrated in the following figure provides a high level of network isolation and also the maximum bandwidth for NSX east-west between host transport nodes. At the cost of a large port count on the switches, each host requires four ports per switch. The VxRail vDS (system) uses four uplinks and the NSX vDS also uses four uplinks.

Figure 21.    Two vDS (system and NSX) designs with eight pNICs